I mostly work out at home -- I do go for a 3 mile walk three days a week -- but that is mostly to exercise my mom.
Anyway, I generally do not watch TV during resistance training -- I like to focus on using my muscles or something. However, I ALWAYS watch TV while I do my cardio -- this has been especially true since I started doing High Intensity Interval Training. Not only is thirty minutes, every day, on an exercise bike pretty boring -- the HIIT training kind of kicks you in the posterior. I find that I need the distraction of something really fun to watch at the top of those nasty peaks -- otherwise I would just stare at the little red display, praying for the next minute and a half to be over -- peak after peak after peak. I still work plenty hard, but I get to watch Grey's Anatomy at the same time.
In fact, I not only watch TV while I exercise -- it is now the ONLY time I watch any kind of only "entertainment" oriented TV. Other than on the bike, I only watch the news, CNBC, etc., and if I don't finish a "fun" show during one exercise period, I have to wait until the next time I exercise to watch the rest (Power of the DVR...). Often, therefore, I look forward to getting back on the bike to see what happens. (This TV rule does not apply for "movie night" with my husband -- that is categorized as quality time and well worth the investment.)