most bike shops will see you right, idealy you want to test ride them, you want to be comfortable on it, relaxed and some space to move about on it.
presuming you want it for general off road riding and XC?
look at the specialized hardrock, rock hopper or stump jumper
GT avalanche
Trek (any)
Giant boulder
something a bit more suited to playing about and jumping:
GT chucker, trek bruiser, giant acid
as a guide to sizing, i'm 6ft 2 with a 33inch inside leg and i ride an 18 inch frame.
if your able to wait a little until september-ish most places reduce the prices of the 08 stock as the 09 stock comes in giving you a much better spec for your money.