I use tektro oryx brakes. Properly set up, they are extremely powerful and I couldn't be happier with them. They're cheap too. Keep in mind that low profile canti's (like oryx) are harder to set up initially...you have to make sure the pads are spaced close to the rims at rest for good power.
I prefer to use v-brake pads with them though, since they have more contact and are better quality. A lot of people like the kool stops.