My favorite setup is "two up, two down," a la Steve Gadd (in my case, 10/12/14/15 rack toms). (I've got a picture of this setup in the "
gallery.")
Often times, tho, I'll just take a four-piece or thiree-piece kit on a gig. The four is the standard rack/floor combo (10 or 12 rack, 16 floor). For the three-piece, sometimes I use just a rack tom, other times just a floor tom, depending on the gig.