When I first started using the treadmills at the gym I thought they were a good idea. In a group class I have to show up at a set time, and that often wastes a bit of time, or leaves me feeling pushed in the morning. Then there is also my psychopathic need to compete with every other member of the class, which leads to uneven workouts. The treadmill was a good solution... I program in the speed and the difficulty and then I have no choice but to keep up at a steady pace. With a little discipline you can make sure you don't quit early and gradually up the setting as the weeks go by.
The problem that neither the group classes or the treadmill solved is that they don't engage my mind enough. I always had too much left over that was busy noticing that pushing myself was uncomfortable. I'd be counting the minutes until if was over nearly second by second from start to finish. Of course there were TVs in the main gym room, but when I first started going you had to bring in a radio and tune it in to certain stations to hear the sound, and I never got around to buying a radio specifically for the gym. A few months ago the gym got treadmills that had some built-in TVs on them, and all you needed was a set of headphones. I tried this, and its better than nothing, but honestly watching morning network TV is only marginally more distracting than watching the cars drive by on the street below.
After having been lame about the gym for a few months running I started going back again and something good happened. I discovered that on two channels on those TVs my gym plays movies. Movies are much more engaging and there are no commercial breaks. If the movie is good enough I can almost forget that I'm panting and sweating through it. Since I don't otherwise get to watch a lot of movies (Warren isn't interested in most movies) this is a great treat. This is good, because as is obvious from my period of gym lameness, the promise of a gym shower isn't always enough to get me motivated for the gym.
Of course there is one tiny catch. You're only allowed to sign up to use the cardio equipment for 30 minutes (and really, that's a reasonable amount of cardio at one go). The average movie is usually at least three times as long. So there I am, watching a random 30 minutes out of a random movie. This is fine by me if I've already seen the movie. I'm one of those people who enjoys seeing movies more than once, so seeing thirty random minutes of the Full Monty is a win. I know what came before and what comes after, and the thirty minutes worth that I saw again the other morning was still funny. On the other hand, its less ideal with movies I've never seen before. This morning I saw the last half hour of Billy Elliot, and now I want to see the first part, but who knows when of if that'll be showing at the treadmill cinema again.