edge emulation (missing some consoles; CD-based games come in compressed formats such as CHD; very fast DL speed)
cdromance (mostly has games for CD-based consoles; games come in uncompressed iso or bin/cue; has a lot of pre-patched rom hacks; medium-fast DL speed)
alvro collection spreadsheet (pretty much everything, including many newer consoles; slightly inconvenient to navigate; download site limits to 1 download every 30 mins, can be worked around with vpn; very fast DL speed)
planetemu (largely in french; has a lot of obscure titles other sites lack; fast DL speed)
script that lets you download from emuparadise post-shutdown (pretty much everything; medium DL speed; can occasionally be uncooperative)
ROMs Megathread/Archive (everything, really; slow DL speed; usually a last resort if you can't find something anywhere else)
i don't currently recommend vimm's lair due to very slow speeds and offering nothing that isn't on other sites
sites offering 3ds/switch games get shut down very frequently so i won't be linking them in order to keep this post from getting outdated but you can find them if you snoop around reddit (the 3dspiracy and switchpirates subs in particular) a little
softmodding and loading roms on some popular consoles:
recommended emulators and emulation guides:
games are great. go play some games.