One of the most popular (for good reason) is the Mustang MD3183.
Very comfortable and has a hydrostatic inflation trigger instead of the "pill" that's mentioned above. This way it only goes off when submerged under 4" of water and no amount of moisture will set it off over time. Most manufactures are leaning toward these now for that reason. That and they cost more
You can get one for under 200$ and they are worth it. I suggest you go to a store like west or BP and try some on. See what's comfortable. Go through a full range of motion and note any areas where it rubs you. Treat it like a pair of shoes but more importantly. You'll be in all day.. mind as well be comfortable. If you don't care then I think cabela's has an auto for 99$
