I have a trainer & rollers at home and ride a stationary at the gym...

Stationary bike can be interesting. The ones at my gym have a watts meter, fitness tests, hills program and others. The only problem I find is that the positioning. These bikes have a "sit up and beg" geometry and there is no way I can get comfortable on them or match my bikes geometry. So, I only last about 20 minutes on them.

I find that my trainer is the best for developing power with interval training. I have a Cyclops Fluid 2 and the resistance ramps up quite naturally as speed increases. I can go to a max threashold that makes my head spin and I don't have to worry about riding off the side. It is boring though, there is no other mental stimulation other than spinning & watching TV.

I find rollers best for developing spin. I have a resistance unit on my Minora Mag rollers and can crank it up for a harder work out or leave the resistance low to just spin away for base mile training. Its definatly not as boring as a trainer but can't do power trainig on rollers. I've tried and always end up crashing off to the side or holding back so I don't.