I always say if you only have one board, you want it to work good when the waves are good. When the surf is garbage, just deal with it... you ain't missing much anyway. But when it's good, you don't want you board to hold you back... you want it to take advantage of that rare, good day. So whatever that is for you, that's what you want, IMO. For me that would be a 6'6 EPS/Epoxy round tail hpsb, thruster/quad convertible - as a quad it works good from about chest on up to head high or so, and as a thruster from head high to a couple feet overhead.

Outside of that, a basically flatter, wider slightly thicker version of a typical shortboard (a "modern fish," of sorts) would be best in small garbage up to about shoulder high. Bigger than that and I'd be frustrated...