Bonds all the way for me (not just a homer pick).
McCovey Cove is a long way from the plate, and when he hits (or hit

) them, they are in the water without a doubt. Bonds' HRs are the inspiration for my favorite homerun call of all time:
Jon Miller: "Bonds swings, and its gone!"
I think that sums it up.
Honorable mention: I recently saw Delgado crush one. It hit a lightpole in SBC park that was probably about 520 feet from home.