I dont go looking for trouble when I am flying bombers with one exception which I will address in a minute. However, if trouble comes to me, I find that in certain bombers the best way to survive a fighter attack is to fly like a fighter.
If you are in the B-17 or the Lancaster, your best bet is to make gentle turns and rely on your gunner. However, in the TBM, Il-2, and Ju-88, with their weak defensive armament, your best bet is to fly like a fighter and try to engage with the fixed armament. In all cases you should get close to the terrain or water thus maximizing the chance that the attacking fighter will make a mistake and give you a manouver kill. You should also keep your airspeed fairly low, in an attempt to get the enemy to stall or overshoot. I have 7 kills in the C-47 just from this. The TBM, Il-2, and Ju-88 have a very small turn radius due to the slow speed. I have killed many an inattentive fighter pilot with these 3. The Ju-88 in particular gets no respect, but I got attacked once by two fighters, a spitfire and another plane. I shot one up with the nose gun to the point where he left us and my gunner got the other. We were able to continue to our target safely.
The bomber I have not mentioned yet is the B-26. The B-26 can be flown either way. Its defensive armament is, in my opinion, 2d only to the B-17. Yet it also possesses decent manouverability at slow speeds and an awesome forward firing armament as well. The B-26 is one that I will actually fly as a fighter sometimes. If I am on a bomber mission in one, I usually handle the fighters from the gunner positions, occasionally yanking the nose up to get a particularly close fighter to overshoot, and finishing him with the fixed guns. However, sometimes when defending a vulched field that has all fighter hangars down, I will take a B-26 from the hangar, 1/4 fuel, drop all bombs on the ground in hangar, before I even start, and take off as quickly as possible. Once in the air, I use the gunner positions to take on the vulchers until airspeed is up enough to manouver, then I fly the B-26 like a big fighter. Last tour, myself and another individual did this, and between us we shot down 12 enemy aircraft for the loss of 4 or 5 B-26s. This was almost singlehandedly responsible for the failure of the enemy attack on our field, since with the fhs down, our defense was failing rapidly. Obviously against a really good fighter pilot, you are almost certainly going to die, no matter what you do, but for those that arent sometimes this is your best chance. Even against the good ones, you can sometimes buy enough time for help to arrive.
For those of you that dont think that real bombers were ever flown this way, there are several stories that prove they in fact were sometimes:
-Lyndon Johnson, later President, was flying as an observer on a B-26 mission once. The bomber was attacked by a number of Zeroes, including one flown by Saburo Sakai. The bomber pilot, according to Sakai flew the B-26 like a wildman, almost like a fighter. This was responsible for the Zeroes wasting much of their ammunition and eventually being forced to rtb emptyhanded.
-There was also a SBD pilot in WW2 that was famous for flying his Dauntless like a fighter. He got 2 or 3 kills that way on surprised IJN pilots that thought they had found an easy kill.
-In fact, SBDs, SB2Cs, and TBF/TBMs were occasionally used in to intercept low flying torpedo bombers and kamakazes, while the Corsairs and Hellcats went after the higher flying dive bombers, and enemy fighters.
-Captain Eric Brown, British test pilot, says that if he had ever been attacked in a Swordfish, he would have flown it like a fighter and used the forward gun, instead of relying on the gunner with his weak armament of 1 .303.
-In WW1, the Bristol Fighter was ineffective when used with the gunner as primary defense. It established possibly the best kill record of the war when pilots began flying it like the great fighter it was.
-The real 1st Air Commando Group of WW2, often used their P-51 pilots to fly their B-25s. These guys flew their B-25s exactly like fighters, quite effectively by all accounts.
-Russian Il-2 pilots scored a number of kills on Luftwaffe fighters in dogfights.
-The Ju-88 was actually used as a fighter in certain versions, mostly against bombers or as a night fighter, but occasionally they had occasion to mix it up with Allied fighters, usually with poor results.
-Another bomber that was famous for fighting back was the Navy Ventura patrol bomber. These bombers accounted for numerous kills scored by aggressive Navy pilots.
These stories are the exception rather than the rule, but they do prove that an aggressive pilot with some skill, can do the unexpected, and take a fighter pilot on at his own game. Hats off to the brave souls that did this in real life and lived to tell about it, and good luck to those that try it in the game!