99 out of 100 responses will say Ruger, but if you are looking for the look and feel of a Colt, only the New Vaquero applies. The Blackhawk neither looks nor feels anything like a Colt. Depending on how much you want to spend, you have Beretta/Uberti, Taylors, Cimarron, USFA and a couple of others.
Personally, I'd recommend the EAA Bounty Hunter. Why? Because the Bounty Hunter has the Colt dimension grip frame (Colt stocks fit it), it responds to the same tuning tricks as a Colt (ask Bob Munden if you doubt that), it also has a transfer bar ignition so the cylinder can be kept fully loaded (like the Ruger and unlike some of the ones I mentioned), there is no internal lock (the Vaquero has one) and you can get one new for less than $350. Blue, color-case or nickel finishes in 4.5" or 7.5" barrel lengths.
There is one important difference; the cylinder. The Bounty Hunter cylinder is 1.76" long with recessed rims and nearly the same diameter as a S&W N-frame. That means it will handle the .357 Magnum loaded as it was originally intended, with the long-nosed 173gr SWC over a stout charge of 2400 (or whatever powder you prefer). It will also accept the Hornady 180gr XTP seated to its lower crimp groove. Neither of these will fit in the majority of any .357 Magnum revolvers, much less a Colt-clone. If you really want to get froggy, the Bounty Hunter will accept the .360 Dan Wesson by lengthening the chambers .125" (although caution should be used here as some .360 loads will push the revolver past its limits).
If you pop over to the SASS site, you'll see a lot of shootists that own several Bounty Hunters and will tell you how good they are. Paco Kelly and John Taffin speak highly of them and Taffin has visited the factory in Germany.
The Days of Wine and Roses: EAA's Bounty Hunter .357 Magnum Sixgun