You cannot record straight from the PS3 without a capture card, so far as I know, so the only real choice is a capture card. Capture cards can be a little expensive, I'm afraid. I have a Dazzle, and it works well enough. I got it refurbished, so it wasn't as expensive as it would normally be. I got mine online, but I've seen them in Best Buy and in a couple computer specialty stores. You need a special wire to record in HD, but other than that, everything you need comes with the Dazzle.
The only real problem I have with the Dazzle is that it records in .VOB format. I haven't found a video editor that supports VOBs, and video converters that support it are almost as rare.
I don't know much else about capture cards, but I hope this helps.