http://whdownload.com/
I got all my games from here, I've played them all, and I don't see any problems with them, maybe except Beast 3 (music tempo) but that was fixed with an NTSC patch.
I'm just annoyed as heck at the thought of having to re-download all of my games from a different site, just on the off-chance of some minor improvements. If I use a much older WHDLoad game, what's more likely to go wrong?