I rotate frequently. It’s mostly - but not exclusively - based on the challenge.
For the shotguns, I use a quad Mace.
For the Machine guns, I use a quad Vector or Sinus (they swap out flawlessly)
Those are typically on a sub 6k fully fused build.
For cannons, which I hate, I use a fully fused Assembler build at just a tick over 10k.
Hard raids get a massive 14k dual retcher that has been constantly upgraded for over a year.
Other raids get one of two triple Arbiter/Aurora builds. One is on quad augers, the other wheels.
I honestly couldn’t tell you which of those gets used the most… probably the first once since I can swap the weapons out so easily. That build also gets triple Storms easily swapped out.
In addition to those, I have a build using Little Boys, a tiny cute art build using Cobras, Barrier & King. Lots of fun. I even got MVP once in it. LOL
There’s a big nasty Gravastar build… not OP or anything, but fun.
There’s a build specifically for farming the 20 side missions when I’m too lazy to actually put forth any effort. It’s got the Cerberus cab, tormentor, two lacerators, two maulers…
And then there’s the builds I keep floating around the exhibition… ducks, dragons, dogs… mostly pyres & drones on those.
I get bored easily, so I switch out what I play a lot.
This is another reason I enjoy XO more than most other games. Changing the weapons on a dude running around shooting people isn’t much variety.