I mix and match a lot.
For my main bad, Crash Pad, that does punk rock and roll, my usual rig is a 90's Sovtek Tube Midget 50W head into an '80's Risson 4x12:
For my side band I usually use a 1960's Sunn 200S head with the same cab:
However, I have a number of other options available, if I don't feel like messing with a 4x12. For instance, the Sovtek head with a 2x12 open-back cab:
Or the Sunn with the same cab:
I also have a '60's 1x15 Kustom cab that has been paired with both those heads:
Although I've got a '66 Super Reverb, she's "retired" from gigging except for special occasions. Since that amp was modded to be a 2x10 combo with 2x10 extension cab (see below, to the right), I have also sometimes used the 2x10 combo top with the 2x12 seen previously as the extension cab bottom-- a 2x10/2x12 halfstack.
In church I use a Super Champ XD as a stage monitor, lined out to a PA head, and into a 1x15 bass cab. Other instruments go direct into the PA head (bass, mandolin, acoustic-electric)