archive.org for as long as shit remains still available there at least. Otherwise get on the eDonkey net (eMule, aMule, etc.). Look for the big packs from No-Intro or TOSEC (or Good<Console> ones tend to also be... good-ish but older.)

If for some reason you only want to download each game individually, MyAbandonware.com has ones that aren't from Big N consoles or have rereleases / takedowns issued, and is passable in those situations. Otherwise the best I can offer is to echo on wowroms.