I am currently using two pairs of TW3X2G1600C9DHXNV (total = 4GB) at the full 1600 speed.
The motherboard's factory speed is 1333, but as you may know it was sold as an overclock enthusiast's board so it's capable of using 800, 1333, or 1600/1800/2000 with overclock settings. The board supports dual channel memory only, up to a max of 8GB.
The board is getting a bit old now, but I'd like to get a little more power if I can. I checked the Corsair.com compatibility knowledge base, but it doesn't seem to have changed a lot since I bought my RAM a couple of years ago.
I would like to know if there are any ram types which the board will support which aren't in the compatibility list. There doesn't seem to be any obvious reason why I can't use Corsair CMP8GX3M2A1600C9 Dominator 8GB (2 x 4GB) DDR3, and if that will work it looks like a good deal these days. Is this workable, and if so is it the best I can get now or are there others?
[edit2] Better looking still, at the same price I've seen dual channel Corsair Vengeance 8GB (2x4GB) DDR3 PC3-12800C8 1600MHz Dual Channel Kit (CMZ8GX3M2A1600C8) which seems to have a better latency. If this is likely to work, or if you know of anything that would beat this, I'd be very grateful for such information.
Thank you very much for any help you can offer.
 Added the models currently listed in the compatibility section of Corsair.com for my motherboard:
CMX8GX3M4B1333C9 DDR3-1333 (XMS3-10600C9*8GB) 8GB Kit (4 x 2GB) 1.5v 9-9-9-24-2T
CMV4GX3M1A1333C9 DDR3-1333 (VS-1333C9*2CH) 4GB 1.5v 9-9-9-24-2T
CMP4GX3M2A1600C9 DDR3-1600 (Dominator-12800C9*4GB) 4GB Kit (2 x 2GB) 1.65v 9-9-9-24-2T
CMP4GX3M2A1600C8 DDR3-1600 (Dominator-12800C8*4GB) 4GB Kit (2 x 2GB) 1.65v 8-8-8-24-2T
TW3X4G1333C9A DDR3-1333 (XMS3-10600C9) 4GB Kit (2 x 2GB) 1.5v 9-9-9-24-2T
TW3X4G1333C9DHX DDR3-1333 (XMS3-10600C9) 4GB Kit (2 x 2GB) 1.5v 9-9-9-24-2T