$500 Upgrade Price Point - Advice?

Hey all. I built my personal computer three or four years back and now I am looking to upgrade. I have about $300-$500 to spend and was wondering what would would you purchase as an upgrade? I mostly play WoW but I do enjoy other, more graphically intense, PC games. I have been looking at potentially buying an EVGA GeForce GTX 660 Ti and an Intel Cherryville 120GB SSD.

Here are my System Specs:
CPU:
Intel Core i7 920 LGA 1366 2.66 GHz

Motherboard:
Asus P6t Deluxe V2

Graphics Cards:
EVGA GeForce GTX 260 x2 in SLI

Power Supply:
Corsair 650w PSU

Memory:
Corsair Dominator 6GB (3 x 2GB) 1600

Hard Drive Disks:
Western Digital Black 500g 7200 rpm drives in RAID 0

Case:
Antec 1200

Any advice would be much apprieciated! Thanks