I prefer All-Star #8. It's the only one of the three that I own, and was actually the first GA key that I ever bought. Hard to believe I've had it for 20 years now!
I don't think the cover is that great on the All-Star 8, but I do think the 1st appearance trumps every other comparative measure. The Sensation cover is, well, sensational, and it's the 2nd appearance of Wonder Woman, plus it's got the 1st appearance of Wildcat, so I think it's a pretty desirable book. Wonder Woman 1 is nice, but not as important to me.
So I'd rank them:
All-Star 8
Sensation 1
Wonder Woman 1