Great thread!
I picked up a used Route 66 pedal and have gotten great tones with it - really cool little two-in-one unit, overdrive and compression with separate controls & switches for each. Got it for $120 Canadian, sells for $190 new. Love this pedal!
Pretty sure the overdrive is a TS808 clone, I really dig it. Works great for a little extra gain on a dirty channel, or for a nice warm, slight overdrive on a clean channel. Has a bass-boost switch to help with the usual 808 loss of lows, has some noise-reduction circuitry, as well.
With my old Carvin X100B head, I usually had the following overdrive settings: gain-9 o'clock, tone-12 o'clock, and volume 10 o'clock. I used it both with and without the bass-boost feature (sometimes at high volumes, the bass boost would cause the microphonic pickups on my '74 SG to honk and squawk.)
Just got my JCM 800 2204, so I'm still in the midst of messing around with the settings with the new setup.
I use the overdrive side the most, but the compression is fun, too, every now and then. You can add a bit of sustain & smoothness to high-gain leads, or compress the hell out of clean/twang sounds for that classic Nashville thing.
Apparently, Johnny Lange is a fan and uses this pedal.
And, I'm not a huge U2 fan (though I respect The Edge and their early work), but this is a fun story from the Visual Sound website: