Actually there are still a ton of sites with up to date roms.
emuchina.net (they are ok for mame roms but have a habit of posting them before they are complete)
aceroms (slow as hell, I only use them as a last resort)
mameworld.net (pretty much a mame.dk clone but can be slow when a new release comes out)
dgroms (decent speeds but usually gets all the roms after I've finished)
And if I'm really lost then I just refer to this
site