Tivo. Tivo. Tivo.
I've had one since early 2000 and I can't imagine NOT having one.
The cable DVRs are simply digital VCRS.
The cable company will try to tell you they don't "support" Tivos on their system, and that their units are "tivo-like." Don't buy it. They're trying to make a sale. Tivo's work with all cable company's boxes.
Take your Tivo out of the box and use it for a while. I'll bet you'll feel the same as the rest of us do.