I use the Minoura MagTurbo 850R Magnetic Indoor Trainer. I use this mainly to do my HIIT workouts with my Trek mountain bike. I don't want to put my road bike on there because I've heard it stresses the frame.

I paid around $150 for this and I'm very satisfied. I'm using this 3 or 4 times a week for around 20 min each time though. (HIIT workouts are fast)