The thing about Tube Screamers, though, is that even with the Gain on 0, they're still adding some clipping and other compression things that an EQ on its own cannot replicate. So there is still room for a Tube Screamer, IMO.
I really like the Duncan 805 for its ability to shape the EQ (without going as complicated as a Graphic EQ) as well as doing the TS compression thing.
Personally, I like Rectos. And I find that for my own style and the tone I'm going for, an SD-1 tightens it up better than an 808, and adds some of the bite and attack that neither a Rector nor a TS808 or OD808 naturally have. I really like the Wylde Overdrive for that. It's basically an almost straight up SD-1 clone that's very subtly tighter and grindier, IMO.
The one thing that my OCD always struggles with TS's and SD-1's (not the hot-rodded ones, just the plain standard ones) is that even if you crank the level all the way up, you're barely even at unity gain (on a clean channel) with hot pickups like EMG's. With even hotter pickups like the X2N or the Black Winter, you won't even get unity gain, which I find disappointing. I mean, after all, they still work, since you'll be dropping more gain from your amp on top plus you'll get more clipping from the pedal, but my OCD struggles a little with knowing that my boost is not really boosting, LOL.