I'll start with a few things. I won't post everything now. Its late, and a lot of things I would add are already here.
Nybor's Psychic Imprint
http://archive.wizards.com/default.a...d/mb/20041215a
Is a great way to enhance magic items during casting, or keep a buddy around.
Watchspider
Animal companion magical beast. Never worry about training tricks. Big enough for a small rider. Comes with poison. Look up the old spew handbook for some fun ideas.
Spikards, and alchemy blade from Eberron. Interesting little weapons with fun damage boosts.
Plant companion (dragon mag) Id love to see what people can do with this some day. I feel it has a lot of potential.
Gnome Artificer.
It tries its hardest to do something new and unique. Shame it isn't good.
Vrill- fearless goblin warrior slaves of the drow. Cool looking too.
corral growth, suspension, Shalantha's Delicate Disk, minor servator Create crawling claw, create darkenbeas, sticks and stones, sticks to snakes, syphon and Engulfing terror are all spells I don't see mentioned often.
Aleax is a monster that IF you can beat it, will give you some huge bonuses. Im surprised hunting them isn't part of most builds.