[quote name='Rig']I haven't bought a PS3 yet, but will here down the line.
What size HDD would you guys recommend?
I am interested in running Linux, but will not buy a single movie, and do not need game demos. I would probably buy a moderate amount of games from the PSN. I just don't want to get anything too small or too large.[/quote]
If you're not planning on storing videos, the 80GB SKU's hard drive would probably be more than enough for you. I'm pretty sure you can run Linux via Live CD on the PS3, so you wouldn't even have to install it to the hard drive.
If you do want a larger drive, it will probably all boil down to what the prices are at the particular moment you want to upgrade. If you can get a larger drive for cheap, go for it. If not, just about any size drive would honestly hold you over.
People tend to overestimate how fast computer storage space will fill up. The computer I'm on at the moment has a 250GB drive (so, really 232GB), There is over 100GB free, despite there being like 500 songs, dozens of games, and so much other crap stores on here.