I think BMX bikes are the sh*t. There's some amazing tricked out stuff in that realm, the sky's the limit.

A ss BMX bike was my ATB through most of my teenage years. Took me through all of the deserts and mountains of L.A. county on damn near ss granny gear. I remember scrounging all my money to buy the cheapest 20" "road" tires I could find and extending the seatpost up to what looked like a ridiculous height. But it suited me well, on both dirt trail and pavement.