HD PVR will cost 150-200 and record in hd, while doing all live h264 encoding on its own, while you can get elgato's eyetv software for mac.
Elgato has some sd capture devices that come with eyetv software that you can use on mac. And if I'm not mistaken, they also have a new hd capture device, but hd pvr is more suited for recording gameplay.
DVD recorders record in SD, but you also have to get a program that transcodes .vob files into more suitablae mp4 files like avidemux or handbrake.
All 3 options work with a mac, but there are lots of other of options that work under windows as well.