For us, it was AndyMark Super Shifters and 6WD. Off the gearbox, we went 24:22 (or was it 25:22?) to skinned-and-treaded AM FIRST wheels (diameter about 5.5" in the end). I realize it's a little counterintuitive to gear back up in chain and sprockets, but it was a little cheaper than fiddling with extra shafts and we wanted to use the onboard encoder. The end result was around 13 fps (could've sworn it was 14, though a re-check of the spreadsheet says otherwise), enough to be one of the fastest robots at Chesapeake*.
*We thought we were doing well to get seven laps in a match. Then, after packing up and sitting down to watch eliminations, 2016 goes and clocks nine. Showoffs. 