Well, depends on how, er, "good" they need to be.
There's always the old standby, D D D Delta (if you don't know it let me know, but I think everyone does this one).
I personally like Yell Like Hell...it's pretty good. My chapter also has another chant that one of the other alums said sounds like a fraternity chant...it's like "Boom bam hot damn who the Hell are we?" If you want any of the words, just holler.