Icewind Dale 2 for using 3rd edition rules.
Other games that use 3rd edition rules
Lame npcs that have nothing to say, nothing but pack mules. (BG1, NWN)
Romances that suck, they're really not "romances" IMO (Kotor games)
Unkillable monsters, unless it's done a special way (Bloodlines werewolf)
Bad voice acting
Bad soundtracks