I don't know any other good main site, other than ebay itself, at least the customer service it's pretty good there.
I know your pain if anything goes wrong with Aliexpress, to summary a long story short, I bought a small Video converter, it arrived damn broken in half, took pictures, told the seller (who didn't bother to reply for a few months), started to talk to Aliexpress customer service, and I don't know, I might have talked to like 10 different people there, escalating the case a couple of times, etc... next thing you know, they decide on favour of the seller and give him full payment because I failed to post the broken!!!! item back at my own expense (even though I was asking the seller or themselves to provide me free postage and I would gladly sell it). Fast forward the story, and maybe 6 months later I somehow got my refund....
But it made me think, if this has happened with a mega tiny purchase, if one buys something expensive and it goes wrong, I think one can say goodbye to his money!
I've decided to use Aliexpress for emergencies only, when I cannot find whatever anywhere else... otherwise, leave it. Even if I need to pay a little bit more, it's your own peace of mind and sanity what you're paying for
I'd be interested if knowing other good shops as well if anyone knows any.