I have the AttitudeSD v2s, and I'm very pleased with them. I think that they are the best value of the Fatshark lineup, because they have a great picture and come with headtracking, a vTx, a built-in vRx, and a camera.
The only other two options IMO:
The DomHDs are clearly the best if you can find and afford them. I flew with them at Flite Fest last year and they very impressive.
The DomV2s are a good compromise between the Attitudes and the DomHDs. They are modular, which is great if you move to 2.4 or 1.3 in the future (which you almost certainly will if you get serious about FPV).
The built-in DVR of the DomHDs and DomV2s would be very handy, but I chose the Attitudes because of the added vTx and camera.