In a word, Yak9u.
Second on that. Yak has great visibility all around as well. It is light so it accelerates and climbs fast.
Biggest, or the principle drawback, is the armament. Only has 1 20 mm cannon and two machine guns, with not much ammo.
Fuel wise I never had much problem, I'll usually run out of ammo before fuel on 3/4 of a tank.
You really need to be closer than 200 before you start firing until you get a little better. Rarely will I fire beyond 400.
Not very good against heavy bombers unless you like assists.
In dogfighting two things I found helpful.
1. Never follow the tail. In other words, estimate where the plane will be in 15 seconds, don't follow where it is now. Try this, imagine you don't have ammo and you have to run into and airplane to kill it....if you can run into it, you can then shoot it the seconds before.
2. Avoid 'flat turns', that is turning one way or the other at the same altitude. The high and low yo-yo are a must. Someone turns hard left, don't follow the hard left, go up and over left...then you have altitude and conserved your energy...keep doing that to wear them down.
Good luck.