Of all the pedals I've owned/own and/or tried, these will all fit your bill, each with a different flavor:
Xotic AC Booster (most compressed in this list, kinda' like a TS9 but not nasally, great for low to mid gain leads) Xotic BB Preamp (nice high mid peak, kinda' Marshally but very smooth, especially great with neck SCs, great for mid to high gain leads) Jetter Gain Stage Red (the smoothest kind of Dumble tone, great throughout gain range) Menatone Howie (same idea as the GSR above, but with different controls/features) MI Audio Tube Zone (pick the latest 6-knob version, highest gain of the list, unique sound, can be a touch thin w/ certain PUPs/amps)
The two things I like about the Xotic pedals (in addition to the overall great tone) is the huge usable gain range and the post-OD high/low tone stack. It makes them so flexible that it's tough to NOT be able to get your tone out of them or match them up with the rest of your rig.