I just finished playing Gold Digger for the second time, and I really appreciate that Lair of the Wyrm deals in a lot of multiple-option encounters. Being able to decide that Valyndra doesn't give half a damn over if she kills all the miners right away or not, and instead have her shadow serve as an unkillable firebreath? That's pretty nice.
My all-time favorite map though, is Desecrated Tomb.
The first half is pretty exciting, and almost always promises to be full of action for both the heroes and the overlord. Zombies tend to be a rather unthreatening monster when weighed against the alternatives (especially those of the conversion kit), so having millions of them works well to fully offset that disadvantage. Find and protect your weakest party member, or they'll find themself immobilized forever.
The second half, I feel, emphasizes the urgent nature of second edition in a way that no other quest can. Here you have Alric charging at a 15 health black gray defense dragon, as he wields a sword specially catered to deal with that massive defense. But what's more, once Khorayt is awake, he begins destroying everything with the power of a Shadow Dragon, but uniquely, from a range. So everyone is constantly dying and standing up while they try to achieve their goals. If that isn't awesome, I don't know what is.
The only real place I think this map breaks down is if the second half's focus is on immobilizing Alric. Alric's resurrection was unkind, rendering him the slowest man in the world - so unless the players simply lost the first half of the map, it's always going to take him a reasonable amount of time to even reach Khorayt.