ATC

IMO, everyone should learn on a non-assisted device first to build strong brake-hand-always-on habits, and then if assisted braking is desired, get a Grigri because it's more or less the standard ABD. I started on a BD ATC-XP, which worked very well. I would recommend a two-lane device, and to get a

8.5 mm ropes are really scary with regular belay devices. Get the green Black Diamond Alpine ATC or something else that is actually designed for thin ropes.

This is from Black diamond before it was called that. I saw an ATC once with that logo. Sick!

Black Diamond ATC Pilot is a really nice assisted tube-style belay device. It only has one slot though, so may not be as useful for multipitch as something like a MegaJul. For a Grigri style device, the Grigri is obviously a good choice, and I really like my Edelrid Pinch.