One button is nice. I tried one recently at Paul Stuart and found it to be sleek and unfussy. I agree with PB that three seems more interesting with the market dominance of two button suits, but I can't stand the three button models where you see the top button hole in the lapel (3 roll 2, I think). To me it looks odd and a bit sloppy...reminds me of unbuttoned, button downs and unbuckled monks. Just my .02.