Well, there's Bridget
Mm... Yeah, bottom-tier classes, essentially.
MT, Frenzied Berserker is a trap, albeit not a weak class, the Survivor, of course, and the 10-level "hey, I can has shocking burst!" 10-level class in one of the completes. Oh, and all but first two levels of Arcane Archer and Shadowdancer.
Pathfinder's take is significantly nicer, all around. Of course, these prestiges suffer in comparison partially due to the power creep in later books.
Fighter is not a trap, it's merely a baby trike. Also a potential Suel Arcanamach, and thus a potential Sublime Chord.
Arcane Trickster is not a weak Wizard, it's a magical Rogue. It's still a weakish class.
Dragon Disciple isn't any sort of a caster, it's a Melee monster (but, see Pathfinder)
Healer... Yeah. Okay. Sangehirn any day of the week.