I've seen some cheap ones for less than 100 dollars.

All I want to do is record baseball games when I'm at work and watch them later. Will a TV tuner do this?

What are some good ones for this purpose? Also, can any do HDTV broadcasts?

I know most can't do HD stuff. I don't know how much they cost, my computer came with one.

Get yourself a card by Hauppauge. That is all I know. And yes.

HDTV cards are still a ways off from working as well as normal ones.

Also, the ones that have just a regular coax cable input also process the sound, correct? I have a video card with S video in or something and I could play PS2 through bundled software, but it didn't have composite input for the red/white sound cables and neither did my sound card.

Yea I'm pretty sure they process the sound.

Here are some reviews:
Hauppauge WinTV-HVR-950
Diamond Multimedia PVR-660 USB TV Tuner

Those are both USB tuners, and I haven't found anything else.

http://www.avermedia-usa.com/multimedia.html < they also make stuff.

If you want to watch while recording you need a dual tuner. And HDTV tuners exist.

This topic is asking for help on a computer related issue, so It'll go best on the new computer help board. Moving.