To be perfectly honest, the way I play, I can't say I enjoy the board expansions that much. I like the expansions that don't intrude on the original rules too much.
The Reaper expansion was fine, the new adventure and spell cards added a lot more depth and variety to the game. The Warlock Quest cards immensely improved Warlock Quests, because the original quests were somewhat lackluster. However, I found the Reaper bordering on pointless; he rarely ever did anything. Let's note the odds (I am aware you can use house rules, but other than selecting characters in a special way, I don't use any); Rolling a one for movement requires a 1:6 chance, not including indeterminate factors such as whether you use a Speed spell, or a Riding Horse, or whatever. Then he has to have characters within his one-die-roll limit: Realize that there are forty spaces on the board, not including the Inner Region. The reaper has a range of 12 spaces around him, in either direction, with the exception of when he crosses from the Tavern to the Temple or the Sentinel space to the Middle Region Hills. If characters aren't in there, his movement roll is basically ineffectual, with the exception of him moving from one space to another. Now think about the fact that he has to directly land upon a character to interact with that character. Let's ignore the character-within-his-range factor, as that is far too random for lazy me, and assume that the character is already within the reaper's range, and he is the only one. He once again has to roll a specific number on the die; 6 times 6 is 36, a.k.a. a 1:36 chance that on a turn where the character is in range of the reaper, that the reaper is going to be landing on him (and keep in mind that this is not including the whether-or-not-he's-in-range factor, and that the player may choose to not have the reaper land on him, as his movement is under his control). Let's say there are two characters in his range, at different distances from him. That adds another number, which increases the odds to a mere 1:18. Now, with three characters at different distances; this would increase the odds to 1:12. But that's ONLY if the reaper has three characters within his possible grasp, and those are still bad odds. Here's a very simple, very reasonable set of rules to use; the Reaper moves EVERY TURN, as opposed to if you roll a 1 (Alternative: 1, 2, 3 will get the reaper moving). Additionally, the reaper simply has to pass by a character, and then he stops and pours his dastardly dice into the character's hands. This may or may not make the reaper an alright addition to the game, I never played with these rule variations, so I didn't test this, but it seems reasonable. (This is pretty much the same for the Werewolf, if memory serves.)
The Dungeon expansion wasn't great for me, because of the excess enemies and high risk. That wasn't too much of a problem, per se, however the fact that it just sort of stood there for a long time while you gain enough strength/craft (and confidence) to enter. I don't like the way extra boards work; I wish that extra boards could add extra spaces to the outer/middle regions, although I do realize that this is essentially impossible. I dislike the concept of it being a track into one point at the end. Also I don't like the idea of board expansions having their own personal deck, but that's just me, really.
The Frostmarch expansion was also fine, albeit not too different from the Reaper expansion. I think that this is where Alternative Ending cards got their start, but that might be the Dungeon, I'm not too sure. I'm sure most people can agree that Talisman's ending is its weak point; but reading through this alternative ending, it dawned on me that these weren't too good either. In fact, the majority were worse in my opinion. The Crown and Sceptre was ridiculous. The Blood Moon's Horrible Black Void has an apt title. It's horrible. No other word could better fit this stupidly unfair card. "Hey, congratulations on making it all the way to the Crown of Command! Oh, guess what? You lose. Sorry."
The Highland expansion wasn't as bad as the Dungeon expansion, but it still made the board odd in a mutant way. Also, the place was positively layered in objects and followers and that sort of thing, unhealthily rewarding in that regard. In other words, dungeon board was unnecessarily brutal, highland board almost babied you. Whenever we played with it, we all found ourselves hightailing it for the Highland board and basically playing the game on the stupid thing. I naively didn't realize this for a while. (Now I play without any board expansions (although I keep the spells and characters, and the Rune Gates)).
The Sacred Pool expansion was actually my first expansion for the game. I freaking loved it. The quest rewards (especially when combined with the Warlock Quest cards) made the Warlock Quests actually worthwhile after getting a Talisman. I felt like I was actually on a quest, for a reward. (Let's face it, the Talisman just feels like, with all due respect to its relative importance, a crippled old man you have to push on a wheelchair in order to win the game.) The Stables cards were good too.
The Dragon expansion… well, let me put it this way: Whenever I think about the fact that I bought it with money, I go, "Ugh." It positively DOMINATES the whole game. I got sick of those stupid chips that littered the board after a while. I hated how it seemed as though 75% of those cards were terribly overpowered enemies or generally unhelpful items I didn't want. I hated having to keep track of the stupid dragon kings, and I couldn't ever finish a game with the stupid rules it enforced. I stopped playing with it a grand total of two games after getting it. I still play with the character cards, though, although the Minotaur likes to tip over because it was, I assume by accident, molded far behind the center of the base, much to my chagrin. (Also, Minotaur + riding horse = not fun to play against.)
I haven't gotten the Blood Moon expansion yet, so I don't have any opinion yet. Looks good enough.
After realizing that the board expansions made the game worse for me in a way I just couldn't put my finger on in its entirety, I got rid of the board, subsequently making my play experience better. I'm truly sorry if you guys don't agree with me, but it's my preference, is it not? If it's not fun to me, it's not fun to me. And it wasn't much fun with the people I play with either (although admittedly I'm probably the most devoted of any of them).