Indoor Trainers
What's your objective?
Casual Exercise:
If you're looking for a little winter exercise to just keep yourself in shape
the most cost friendly trainers would include: Wind Trainers and
Adjustable Resisance Trainers.
Staying in Shape:
If your a Roadie, Mountain biker, Commuter, or regularly ride your bike for
fitness or
performance you would want a trainer that has progressive resistance,
so your riding experience will be closer to riding outdoors.
Indoor Training:
The most realistic ride will come from the fluid trainers.
The heavier flywheel
and the finer tuned progressive resistance is the
closest you can get to being on the road.