I've had the Mule, Emerald, Abraxas, Crawler, Warpig, Miracle Man, Nailbomb and Cold Sweat (if I'm not missing any out).
I would normally recommend Abraxas for pretty much anything, but for Slash - nah. Mules? - not enough poke, Stormy Mondays - same problem.
I know where itamar101 is coming from with the Emeralds and I'd be tempted to agree - it's the solid crunch in the low mids while still being a hot-PAF kinda pickup. I'd say Riff Raffs will be too agressive in the top end and not chewy enough in the bass and low mids. Maybe a Rebel Yell could get there too. Depends on the amp.
To be fair, and this probably ain't gonna be a popular suggestion, but if you want Slash's tone get some Duncan Alnico Pro's - he's used them for years.