Barbershop V2. Always on. Amazing.
Kind of a weird hill to die on in the Pedals forum, but OK.Honestly I don't see the point: why a pedal?
If you like the overdriven tone of your amp but you'd like to play at lower volume get an attenuator: I love dirt pedals for what they are, effects, but a nice vintage tube amp "in the zone" is the perfect overdrive for me. I generally play a vintage style (custom modded by me) Vox AC15 or AC30 amp or a DRRi, but I often experiment with a couple of Marshall 2x12 and 4x10 cabs, in either case my Weber MASS attenuators are a must. At this very time I'm getting a great classic rock\RnR tone with my AC15 played simultaneously through its Celestion Blue speaker (16 ohm) and a 4x10 Marshall cab (also 16 ohm): with the amp on ~6 I get an incredibly nice OD, extremely touch sensitive, open sounding, just better than any pedal in my possession, for that "natural" OD tone, all thanks to my attenuator.
Obviously pedals are fantastic to get a different tone, but for a "breaking up tube amp" tone, well, just use a tube amp if you have a nice one!