Ive got cantis, Vs and disc brakes (had hydraulic discs and now have cable discs).
Ive never got on with cantis for anything other than a bimble ride. No matter how much time spent setting them up. But, ive never had really good cantis either.
V brakes...ive had xt and thought they were alright. But, stx rc v brakes are my favourite and though they take a bit more setting up than xt, i find them muvh more potent.
I have them on all my bikes that run v brakes. Awsome brakes.
Hydraulics i didnt like particularly, especially when they need to be bled etc.
Avid bb7 cable disc brakes, a real bitch to set up but great when done, especially with compression-less cable outers.
I find them great.
Still my favourite are v brakes though.