1x12 or 1x15 at least. Sometimes 1x12 plus 1x12, sometimes 1x12 plus 1x15, sometimes two 1x12 stacked vertically alone or coupled with 1x12 or 1x15, or sometimes a vertical 2x12 coupled with 1x12 or 1x15. The poll doesn't apply to my reality.
I've had several 4x12's in the past, but then I got a smaller car and couldn't haul them around. Also, I find myself micing my cab at most gigs, so the audience is really only hearing one speaker anyway. That, and when recording, I only mic one speaker, and then maybe have a room mic. So basically, I had three extra speakers not doing anything but taking up space. I tried the 2x12 where you put two different kinds of speakers together, but decided if I was going to do that, might as well play two different amps too and play in stereo. So I was back to 1x12.
Tone comes from running power tubes at full voltage. That means very high volumes, which create many issues.
I crank a vintage 50 watt head into a closed 1x12 and turn it backwards. Loud and glorious, but somewhat manageable. On a tiny stage I'll use a 22 watt head, and on a big stage in big venues I use a 2x12.
I have 4x12's and 2x15's but they haven't left the garage in years.
If you're playing out, compromise comes far more into play than it used to. These days you're dealing more with small venues, cramped stages and a house sound man who tells you he knows his room - doesn't know your band - but he knows the room. As a result, you find yourself with a small amp, usually 15 watts and a 1x12. I'm being told that the Fender Blues Jr. is the most popular amp now.
For years a 4x10 was my go to, but currently I have a Tone King Sky King 1x12 combo which sounds huge for its size (clever cabinet construction). It doesn't have the multi-speaker swirl I liked so much about the 4x setup, but it definitely punches above its weight (sounds more like a 2x12), is less trouble to cart around, and I get less complaints from the band and the sound guy.