I have tried numerous different workout programs thorughout my life, usually to failure again and again. I get bored easily (treadmill anyone?) and I was never an aerobics chick. But ----- I recently found an incredible program that actually works!
"Insanity" by Beachbody is amazing! It is a 60-day, 10 dvd body conditioning cardio program meant to get you fit fast. It does recommend you already have some level of fitness, as it works you hard! Check it out a:t www.getinsanity.com This is not sissy cardio aerobics! It is pure cardio, with lots of plyometris and resistance training. No special equipment or gear needed.
It is a little pricey, but well worth it. I have tracked my progress, and I have seen tremendous results after just two weeks. You have to be committed, but it is amazing how well it helps you get fit. I am doing it as a vegan, which is a little rare, but I have been able to make it work!