Rode BMX bikes up until 1989, when I bought a Haro Extreme MTB.
I raced it that year, and did very well. Logged 4K miles in 3 months that year.
Stopped riding to play pool and do other things, and got another bike in 2004. A Giant STP. I very quickly switched it to single speed, and have been riding mountain bikes ever since. I spent a summer back on my old 24" BMX cruiser, another summer on a 20" BMX, then built up a custom 24" MTB with a rigid fork, and am still riding that. Took a trip to Whistler, and then bought a full suspension bike, I really enjoy the gravity stuff... I have a Trek Session 77 and a Norco Empire 5 for that type of riding.
Due to an unfortunate incident on some large dirt jumps, I've started riding on the road again, picked up a SS Moth that's pretty fun.
I live in Oregon, near Eugene. (USA)