I really LIKE the spinervals videos -- they are truly focused on getting your bike form and endurance up to snuff...very hard videos, but very good training. I also found it improved my general bike knowledge overall as well.

And I love the fact there are "real" athletes on these videos, triathletes, ironmen, etc. who actually sweat!! Finally, someone who sweats like me! ;-) Those Jane Fonda thong and leg warmers days are OVER for me....