The Rolling Stones were indeed one of the most prolific bands of their time and rest somewhere behind Credence Clearwater Revival and The Beatles. Let it Bleed, Sticky Fingers, Exile, and Beggar's Banquet are all essential. From there it's more of a personal thing, picking out what parts of their sound you dig and going from there. Their early albums do have some filler, sure, but I mostly take it in stride, because they're still a tight band with a thick sound even when their material is less than inspired.

Damn, I haven't listened to them in a while. Gotta get back on track.