Until now it was just Uboat War Ace Campaign (plus a few mods) - best immersion into the WW2 era, to my opinion, with its lots of operations that make me feel like being part of the war.
Now I'm trying a hybrid: the campaign files of UWAC (so that I have all the war operations modeled in the game) merged into the NYGM TW 2.2 basic game, to keep the boat realism and the sinking model of ships. Of course, I also had to import into NYGM the missing boats and airplanes used by UWAC. So far (4th mission, early 1940) no CTD and everything runs fine.
To this I also added some personal changes, like reenabling the impact torpedo switch, transparent water and others.
With it, I use SH3Gen and will try to adapt SH3Cmdr for NYGM.

Same here. I've not even bothered with the 'stock' game.....

Right now I am running GW1.1a only.

GW 1.1a and SH3 Commander.

Ditto, with a few adjustments thanks to SHC Commander.

RUb with SH3 Commander plus Fubar's skin pack.

I run mostly plain SHIII. The only changes are a few minor tweaks using the game's config files and the Radio Log Lite mod
.

GW1.1a only, although I'm looking at possibly trying a couple of others out after I finish my current career.

GW 1.1a, GW 1.1aKidsMod (nice change of pace), torpedo/Deck Gun/Flak gun power mod, and SH3Commander (Of course).