no real budget since anything running without a fan is probably not going to be top end/top dollar. Just want to grab something with the best oomph without a fan.
well if cost isnt a problem, then why not get 2 4870x2's and water cool them?
on a more serious note, what do you plan on using the card for? if it's for an HTPC, you could get away with a passively cooled 9500GT. MSI makes one with some fancy heatpipe thing on it, and that particular card also has an HDMI port, which is ideal if this is for an HTPC.