I think I'd say cuffs, but that's only because I've recently seen some great suits with cuffs. At the moment, none of my suits and pants are cuffed.
I prefer the belt. Personal preference for the most part rules here. But I like when either my jacket is off or unbuttoned, having that shiny buckle for all to admire. I will counter with yet another age old question: On the pant, cuff or no cuff?
Quick question: suspenders or belt?
