I use Spinerval videos extensively since a large part of my training year is spent indoors on a trainer. I like the tapes because they are designed to work on specific aspects of cycling techniques. I have a tape for climbing, a few on recovery and technique, time trialing, interval training, etc. I love having the tapes for when I can't get out on the road.
I also go to Spinn classes in the winter at the local YMCA. I'm lucky to have three instructors in the area that are top notch and because they are all cyclists they teach spinning to improve cycling technique.
Sometimes I do just pop in a Tour De France tape and ride with the boys. I climb when they climb and sprint when they sprint, etc.
If you are training (working on specific techniques) I recommend getting Spinervals or something like that. If you just want to be on the trainer for an unstructured workout I think the Tour De France tapes are more fun.
traveller
"It never gets easier, you just go faster." -- Greg LeMond