I'd use a fully cannoned 110. You can just hose down bombers with it from long way out. Head on if you can. But you have to be careful with friendly fighters around. I hit a B17 which was being tailed by a gaggle of fighters. The cannon rounds must have hit a friendly too and I killshootered myself straight back into the tower.
I also like the Yak 9 with the big cannon.
My favourite fantasy is to get the drop on a buff mission in a 110, just as they are about to drop their bombs and kill 9 or 10 of them at once. One day, one day
