the problem as i see it is trials is to boring to watch to ever become something as big as bmx and skateboarding, in other words trials will never become that big because its fundementally flawed
Youve asked a question that has no answer, obviously everyone will just either make guesses at whats good or tell you that their own bike is the best. I suppose the answer really is what ever frame your used to riding
i would be tempted to go for something off tarty or wait for a full mod to come up on here afterall you can get some cracking bikes for a really good price second hand