I'm running a 1TB hard drive in my PS3 (have had it for 2yrs). So far no issues. Have several PS+ games on it and still have over 500 gigs free. As long as you get a 2.5 inch drive, you should be fine. Be careful, some drives say they are 2.5 inch, but run double platters and are too big (in physical size) to fit. Investigate the customer reviews to make sure someone has placed it in their PS3 just to be sure. Here is the one (I think--it's been a couple of years, but I seem to remember the PS3 recommendations) that I bought: Samsung 2.5 drive
. There are others, so you might want to comparison shop.
You also have a choice--the big drives are now cheap, but there are 2.5 SSDs that will also work in the PS3. They are faster, but do not have nearly as much capacity. Sid Schuman (PS Blogcast) bought an SSD and loves it. He said that games that require lots of texture loading (RAGE, for example) are greatly enhanced by the SSD drive and that he doesn't experience "texture loading" that non-SSD drives do.
Personally, I find the large headroom more appealing (for this gen.) and probably won't change with the PS3, but I may consider an SSD depending on what the PS4 allows.Edited by shadowlock - 3/10/13 at 1:47pm