Hi Jen,
There are tons and tons of good tapes. It really depends on what you want to do. There are step videos, kick boxing, and lots of interval training. You can go to
www.collagevideo.com and get about a 60 second preview of there selection. Also you can go to
http://www.videofitness.com/reviews/ for video reviews, these girls are over the top with tapes and working out.
Personally I use a really old step tape of Susan Powter for my cardio, she's a good instructor and the moves are basic, nothing crazy. I also dabble in Joyce Vedral for my weight training, her books are fantastic. Now her video's leave a bit to be desired, her form is really bad and she skips reps. If you know what your doing and don't mind pausing the tape now and again she has a great concept. But there are sooo many more, shop around and see what you like.
Hope this helps, pm me if you have any other questions! BTW, I have lost about 30 lbs and only have about 10 more to go. Staying active and eating smart will get you there, it's just takes a long time.