Basically anything, post what you have and maybe we can come up with something.
I have basically everything from the original 386 besides Deoxys (damn event never came to New England D:<)
Here's a short list of what I have to offer, and again, all things are legit, so don't think I'm ripping you off here, XD.
Mew from Toys R Us
Celebi from JAA
Jirachi from the Colo Bonus Disc
GSC Starters (breed from Colosseum Pokes)
Manaphy (Offer well for this please)
(Bronzong and Belossom I caught myself, while all the others were obtained in trades, just throwing this out there if anyone cares)
And... name anything else if you want it. And note: if they can't be breed, they're most likely cloned. I don't care if you trade me clones either, just as long as they were caught legit. Specify that if you want, but I won't ask questions, I'm just assuming that most 3rd gen ones are cloned.
Have any questions? Ask away.