Ragdoll Corpses by GoblinBob
Adding an amazing death effect seen in a lot of modern games... ragdoll physics :3
Mystcraft by XCompWiz
Mystcraft brings elements from the Myst series of games and books to Minecraft, as well as allowing players to actually write and travel to their own Ages.
Gambling Style by Fuzs
Overhauled villager trading gui for far better usability and a lot of convenient extras.
Block Control Keys by Lothrazar
Key bindings that push, pull, and rotate blocks. Pushing and pulling is restricted to only horizontal. The block rotation key turns stairs and logs into their different positions, as well as carving things like stone brick and sandstone into alternate versions.