You want to plug an antenna or cable into a capture card and record some stuff? Me too. I got the Hauppauge PVR-150. I read a lot of nice reviews on it before I bought it. I'm new to this and the card was fairly easy to use. Not a lot of inputs on it to confuse me. The card does the MPEG-2 encoding, so you are not wasting CPU cycles.
So, if you are looking for something fairly simple, I would recommend the PVR-150. There are a few forums around to help support any issues. Hauppauge's support is not bad either.
There is a Windows MCE version of the PVR-150. You don't need that unless you are running MCE.
Make sure you have a decent video card and hard drive space.