I won a new GSI Halulite kettle in the fall that I loved instantly. I'm sure that I'm going to carry it regularly. It's ultra light and holds about 2 cups, so just right for a quick brew-up. It's also got a pretty wide opening so I can store some stuff inside. A pocket esbit stove, a couple extra esbit tabs, lighter/matches, bandana and a collapsable cup fit in nicely, so you can make a nice little brew kit out of it.

GSI Halulite Kettle

The honest truth, though, is that I'm not picky. I'm just as likely to use an old spaghetti sauce can to boil my water in. I do always carry a water bottle & SS mug or my canteen kit as my primary kit.