I've built Aion, PPCB, Moonn, Fuzzdog, Musikding and one from Uraltone (not sure if they even ship internationally). All of them have been fine, although PPCB has probably been the easiest.
With Fuzzdog I would suggest you pay attention to which boards have 9mm pots, that's one pitfall I've fallen into due to not paying enough attention. Otherwise I haven't had issues.
I've also built one board from MoodySounds and have one on the way from Electric Druid, MoodySounds build was fine (except where the hell can I get a C2k pot!?). I've also heard GuitarPCB is fine, haven't built anything from them.
Pretty much the only one to avoid is PCB Guitar Mania based on what I've read. Some of the boards work just fine, but others don't work at all and you might not get any customer support. It's tempting since the prices can be very low and they have a huge selection, but it seems the huge selection is due to not even verifying boards before shipping and copying other people's designs (badly). This is all hearsay, but it's consistent based on multiple sources.