umm the best one i got was a untouched WISHMKR jirachi.... for a palkia that i had got in a trade about 2 hours before, which i traded for a hacked (i didnt hack it, i was trading over the gts and i got some hacked pokemon in return which i wasnt to pleased about) celebi (on route 203 rofl) o.o
so in other words, i got a WISHMKR jirachi, indirectly from a hacked celebi.
the only time i have ever said thank you to hackers lol.
other than that, i havent had any outstanding trades, but i had some decent ones involving shinies.