There are so many types of bikes. I've ridden plenty of different kinds of bikes...but I've never ridden a true track bike or a folding bike.
I have ridden:
a fixed gear, a no-, front-, and dual-suspension mountain bike, 26er; 29er, disc brakes, a road bike, full carbon bike, a time trial bike (only for a short ride), a polo bike (as a converted single speed), a penny farthing, a tall bike, a recumbent, a trike, a tandem, a BMX, a cruiser, a mini bike, and probably some more.
I guess I should work on trying out those that I haven't ridden.