Mice: Logitech, by far. I have an MX510 an' it's great; eight buttons, corded, lightweight, responsive, ergonomic an' relatively cheap. The newer MX518 an' G5/G7 look even better. The drivers do suck, but thar be a third party utility called LogiGamer that makes up for that.
Keyboards: Logitech has one very nice keyboard comin' out (G15) that I will probably buy, but th'rest all have that weird layout with th'insert/delete keys. Same goes for th'Microsoft keyboards.
Sound: I use a pair o' Beyerdynamic DT250-80 headphones. They are closed (I personally wanted th'isolation), sound fantastic in both games an' music an' like all Beyer headphones, are practically indestructible. Somewhat expensive, although I got them at a considerable discount. Headphones in general are far superior t'speakers for games IMO.