I would appreciate opinions for this question but for SATA3. I am looking at the 120GB as being in my price range and will be used as a boot drive. So far it sounds like the Intel 510 is the best reliability with only a slight cut to performance. (As many of posted, probably wouldn't notice for my use anyway).
Heck, my current (old) system has 2 x 300GB drives and both are only 1/3rd full, so its not like I need a ton of storage space (yet). I am thinking of either moving the second drive over to be a data drive on my new machine or get a cheap 1TB.