Traditional on a budget? Uberti Cattleman, one of the less-expensive variants, and a set of Wolff Springs (another $20 or so; the ejector spring doesn't fit, so keep the original. The rest all benefit from replacement).
Want a modern revolver that looks and balances like a SAA? Ruger New Vaquero. Load 6, no worries. But it's fair to say that the action feels NOTHING like the real thing. That's not to say the trigger isn't wonderful; cocking the hammer just feels really different.
Want the best shooter for a reasonable price? Ruger Blackhawk or Super Blackhawk. There's a lot to be said for sight picture, believe me! Or, to go traditional, a Cimarron Evil Roy, actually a Uberti that's been highly tuned and has traditional-looking but different sights.
Got some cash? US Firearms if you want a really nice shooter, Colt if you want an investment.
Just my humble opinion.
And don't neglect springs. Unless you buy a real POS, springs will do a lot to tailor a SAA. The higher-end stuff like USFA or Evil Roy guns come as you want them. But my Uberti Cattleman Millenium cost me $265 brand new, and, though the trigger pull and the action feel were lousy when I bought it, a set of Wolffs slicked it up really nicely for 20 semolians.