Baklunish, Suel, Keolandish, Oeridian and Flan for when your character visits the world of Greyhawk. Then add a bunch of Realms, Krynn, Eberron, etc languages, and you'll quickly run out of slots.
Of course, with all these suggestions people are throwing around (including the usual outsider standby's), the big question becomes... WHO is going to teach your character those bizarre languages? Personally, as a DM, I would never allow a PC to take a language unless it was actually possible for them to have learned it in a realistic situation. Starting languages must be common languages spoken around the area the PCs come from (and all players must choose a home region when they create their PC), or they must actually find someone who can teach them a new language. While cool, there are not many PCs in my campaign that can speak non-standard languages.
Doesn't matter how many language slots they have.
Denis, aka "Maldin"
=============================
Maldin's Greyhawk
http://melkot.com
Loads of edition-independent Greyhawk goodness... maps, magic, mysteries, mechanics, and more!