Zumo 550. No problems at all operating it with gloves.
That thing is friggin awesome. It's wired to my StarCom so it'll give me directions (very handy - the GF and I are going on a nice ride over the weekend and it's going to guide us along the way).
I loaded a crapload of MP3s on a SD card so I also get music.
All I need is the right cable so I can use my cell phone (cable for the StarCom - to - Zumo for the microphone; cell phone - to - Zumo via Bluetooth). Not that I really want to chat while riding, but it would be handy.