660p or Crucial P1 - avg case you're still going to be 2X faster than a SATA SSD. The write cache is still ~20 -25GB when nearly full so it's not a concern unless you're moving data center levels of files.
Large write sessions, like a 200 GB image restore, etc., would indeed be faster with the EVO; but, typical gaming, the half-second shaved off of reads would be unnoticeable, so, the 660P is a screaming 2 TB bargain, IMO