MLPSunsparkle was working on a list of some kind...I am not sure quite what is happening with that though.
I tend to just google for G3 and compare sites, since there's no one single site that covers all aspects of G3 for me. I am kind of wary of using sites for G3 that have errors for G1, though, because I am less likely to realise if it's an error for a generation I know less well.
So I compare sites, but don't have a checklist.
Actually, someone on here posted or mentioned a checklist some timeback, because I have one downloaded on my PC somewhere. It is kind of image intensive for me and I haven't used it, but there must have been a thread about it somewhere going back maybe six months?