Here's some stuff from Player's Guide to Eberron and Five Nations.
Gatekeeper Mystagogue (PGtE) - -1 with druid entry, +0 with non-druid entry. It advances or grants an animal companion, has 9/10 spellcasting, and has a bunch of features that are useful against aberrations, but not much else. Though it does give you poison immunity, slippery mind, and a kind of dimensional lock ability. Losing wildshape is too much trouble for druids, though.
High Elemental Binder (PGtE) - -1. You lose a level of spellcasting, but get an elemental companion. And a bunch of features that would be real useful for gishes if only it didn't have d6 HD and 3/4 BAB.
Revenant Blade (PGtE) - +2. This class single-handedly (well, two-handedly) made dual-wielding viable. If you're an elf and you're going into melee, take it and never look back.
Knight Phantom (5N) - +1. A much better version of the eldritch knight, even if the prereqs are wonky.
Dark Lantern (5N) - +0. It's not really as bad as I remembered it being, just lackluster. It gives you a bunch of rogue special abilities and full sneak attack progression, so it's not too bad compared to a straight rogue.
Cyran Avenger (5N) - +0. A five-level gish class with smiting. Not terrible, but not awesome, either.
Bone Knight (5N) - +2. Sacrifice a caster level for a bucketload of immunities? Certainly!
Silver Pyromancer (5N) - +1. For setting things on fire, it doesn't get better than this.