I bought a 400gb sata 3.0 from outpost last week for $140.. it's now $210 hehe
ata 100 = pata or ide i believe
ata 133 = " " " " "
serial-ata 150 (aka SATA 150) = SATA 1.5gb/s
serial-ata 300 (aka SATA 300) = Sata 3.0gb/s (I think this is also SATA II, someone correct me if I'm wrong).
the typical sata is 150, but 300 has been declining in price lately. From what I understand, you can run a sata 300 drive on a 150, but you will only get 150 speeds. Likewise, 150 drives on 300 channel will run at 150 I think.. I know 300 is backwards compatable.
Basically... 3.0 is the way to go from how I see it.. but then again, I'm building a server, so I need teh speedz!!!11