I'd like to start a discussion gleaning people's opinion of the two best characters for each sphere. I chose 2 because it can often be too clear on the single best character for the sphere, although there still would probably not be consensus. Also, although this is written with a solo player bias I tried to consider multi-player as well.
My comments will be more directed to solo players than multiplayer (but I will include a few comments for them as well, since I play that way occasionally). To be blunt, even though your stated intention was that you were directed more to solo play, it seems that some of your ideas are more suited to multiplayer (Eowyn).
Leadership: Dain, Theodred. Dain is a king indeed for dwarven decks. The impact he has on them cannot be overstated, particularly in giving utility (willpower) to all cheap allies, which is a great boon to tactics. Also, Dain is a supreme defender (or attacker, or both with Unexpected Courage, which Dain is a prime candidate for). Theodred is in many ways Dain's opposite, good in any deck where Dain only excels in certain ones. It's good to boost Theodred's will (Celebrian's Stone, Dunedain's Quest, Favor of the Lady) as he will probably quest every turn. Theodred doesn't have great stats, but his low threat and utility put him in the top two of Leadership. Honorable Mention: Aragorn (Core)
Definitely won't argue with these choices. Although right off the bat, we see the beauty of diversity in this game. Dain gets my "rockstar" vote, but obviously is pretty limited to running a dedicated dwarven deck for him to truly shine. But with the race being the strongest in the game right now, he pretty much HAS to be one of the best Heroes from this sphere. Honestly, I use Theodred a LOT. As much as I love Aragorn (either version), I can't seem to break my Theodred resource addiction. Caveat: Aragorn is a much more "versatile" hero. Better all around stats, built in readying ability, and specialized attachments that make him ridiculously good, and a monster in multiplayer games. It really is a toss-up between him and Theodred for my second choice. Theodred, on the other hand, is great in solo play, since you don't have the option of relying on any other players to throw resources your way from their decks. Downside is that he pretty much becomes a dedicated quester with low willpower, but that can be oversome with some attachments inf needs be. And in a pinch, you can always use him for something other than questing.
My choices: Dain and Theodred, for pretty much the reasons you stated.
Spirit: Glorfindel, Eowyn. Glorfindel is Spirit's only high attack hero. In addition to being a great quester with Light of Valinor, Glorfindel races through locations with Asfaloth. He's a superhero with just those two cards, letting him quest and attack on the same turn, and his rock bottom threat of 5 is of course terrific. Eowyn is stellar at questing or other will-related tasks (ie Gollum's escape tests) with the highest will for a hero, and is a handy sink for dead cards and therefore can change the make up of your deck (making it better to include those 3 copies of Steward of Gondor). To me, there really aren't any attachments that beg to be put on Eowyn. (Side note, Spirit has the least amount of heroes, at 7--other spheres have 8). Honorable Mention: Frodo
Glorfindel is a no-brainer here. From the get-go, he jumped over Aragorn to become the hero with the best "bling" (attachments). Outside of defending, there's not much he can't do well.
But Eowyn is going to be my first major split from where your comments lead. I will admit to being like every other fresh player when I started… I ran her in EVERY deck, she's just too easy to put in there for questing. But after that, her abilities are just….. absent. About the only thing that can be said for her is that she can burn unwanted cards out of your hand. Let's think about that statement… If you have that many cards to just burn for willpower, you may need to retool your deck. While she clearly has the best willpower for heroes, this game now has TOO many options for generating willpower in other ways to hamstring your fellowship by relying on a hero that can only do ONE thing. Success in this game has proven to be solidly tied to "action potential" - gaining extra questing, defending, attacking, text abilities, etc from your heros. Glorfindel, Aragorn, Boromir are example of these built in. And you can use them in multiple phases successfully because of their abilities AND stats. Let's say we ready Eowyn once she quests. Then what? Is she really the hero yo plan on defending or attacking with?? Now with that all being said, she does add extra value in multiplayer BECAUSE of her "card burn". Even though I poo-pooed it a moment ago, there is a difference between using her in solo games, where she is very limited in what a solo player can do with her, as opposed to in a multiplayer game where she can "quest tank" in the place of two different heros. The ability for, say, three people to potentially push her willpoer to a value of 7, for example, means that another player has the potential for saving one of their heros from needing to quest. That's about the only way that she can generate extra "action potential". So even though I have tried to break my friends that I play with from their Eowyn addictions, I really don't mind when they plunk her down in a game (one less hero slot they might use to conflict with any of my chosen heros as well…. lol).
The hard part is to choose who else from this sphere would I choose instead of her. Well, it really is situational. I use to run Dwalin a lot in my dwarven deck to try and get some threat reduction. But realistically, I found that I rarely got to trigger his response… and with the release of the first Hobbit saga, the dwarves now have some better "sidekcicks" to Dain (Ori/Nori) that provide more consistant effects in a dwarven deck. Eleanor is actually a great pick in multiplayer (not so much for solo) where she becomes a great CYA for a game where you have to pull more encounter cards (thus potentailly more treachery cards)… cuz not every deck is going to be running the Spirit cancel cards. But I think my second pick is going to have to be Dunhere, because while his ability is pretty direct and up-front, he provides you a very unique ability that is nearly impossible to replicate in the game. Being able to attack an enemy before it can even engage you (negating any engagement triggers AND preventing the shadow card draw) is HUGE. I actually don't use him that often (since I tend to run dwarves or Glorfindel), so perhaps this choice is a bit hypocritical. But for all around usability that isn't tied to dependancy on a dwarven keyward, he's my pick
My Choices: Glorfindel, Dunhere
Lore: Elrond, Beravor. (I really wanted to include Strider here, but ultimately thought Beravor edged him out because Strider needs a deck built around him slightly more and Beravor has lower threat). Elrond even without Vilya is a strong hero, able to amass a multi-sphere army of allies. Besides his Elven Ring of Power, other terrific cards with Elrond are: Warden of Healing, Light of Valinor, Imladris Stargazer, Gildor Inglorion, Unexpected Courage. Beravor is the quintessential hero that's good any deck. Solid 2W, 2A, 2D, 4HP stats, and a great card draw ability. Even though you can't use Unexpected Courage to draw more cards, it's still a good attachment for her to be able to utilize her other stats. I've especially found her good as a defender with Burning Brand. Honorable Mention: Aragorn (tWitW)
Easily the hardest sphere to choose from for me, because it's probably the one that I use the widest range of heroes from: Beravor, Bilbo, Elrond, Loragorn, Bifur.
And you won't hear any major disagreement from me with your choices or reasons for them. This sphere is really the "workhorse" or "handyman" in this game so far… Elrond is a beast. Even with his high threat cost, his abilities to build and heal a multi-sphere army are insane. Add a ring and ally or two, and the game gets crazy stupid real quick. After that it becomes VERY situational. Bilbo is great for single player (extra card draw every turn? Yes, please…) but pretty limited in use (still think that only one willpower for him is just dumb…), and loses potency the more players you have. Loragorn will be a mainstay in any secrecy deck (assuming they finally flesh out that mechanic to make it worth it). Berevor is just crazy good. Even being nerfed, she just gives you a wealth of options with stats and abilities (putting UC on her can almost guarantee you a chance at victory). My unsung hero is Bifur, who I find I use in more deck than any other hero (Theodred is pretty close). While his stats aren't the best and he doesn't "do a lot", his low threat cost and ability to move and pay for expensive/powerful lore cards has made him pretty much the only dwarf I use regularly, let alone outside of a dwarven deck. So while Elrond is by far the "beast" of this sphere, my picks for general all-around play and non-situational usage are…
My Choices: Beravor, Bifur
Tactics: Legolas, Boromir. Tactics was, for me, the most difficult sphere to determine, with no clear winners or losers. First, the dwarven heroes (Gimli, Thalin) would most-likely have higher stats courtesy of Dain, which could affect their standing. However, I considered the characters separately to get these ranks. Also, I haven't played Hama yet and feel that he could be one of the better Tactics heroes if played well in a deck that highlighted his event ability. I have found Legolas to be a strong and reliable character in that he prevents you from getting bogged down. Blades (of Gondolin, Rivendell) are good on him, as are other attack boosters and Hands Upon The Bow, of course. You will get a lot of milage out of Boromir, who (even more than Legolas) benefits from W/A/D boosts such as the Dunedain cards. Even more, you will have to reduce threat for Boromir, who comes with a hefty 11 threat and will raise it even higher with his readying ability. Also consider ways to heal Boromir because he could be taking a lot of attacks. I like Boromir because he can be a one man army. Honorable Mention: Beregond.
Hardest one for me to use, since I don't run them very often. I've now started using Thalin in place of Dwalin in my dwarven deck, but he's kind of a "Theodred-lite" character. Not really who you WANT to quest with, but in a dwarven deck his ability kind of puts you in a "have to" situation… Boromir has pretty much been the top-dog in this sphere for his action potential ability that is difficult to match elsewhere (now that there are more threat-reduction options in the game). I like Legolas and Brand, but I can't really consider them at the top since their abilities are pretty much limited to great success within Multiplayer games (especially Brand, which is too bad…). Gimli is great, of course, but I hardly even use him in my dwarven decks… I think that two of the more recent heroes are great for this sphere, Hama and Beregond. Hama makes it viable to run a tactics-lite deck with other spheres just for the ability to keep pulling those great events back into the hand. And Beregond is gonna be amazing for all those new siege locations and ability to reduce the need for resources in a Tactics-heavy deck.
My Choices: Boromir, Hama