I think the Tri-Wing was the best if I had to pick one, because from what I understand it had a lot of maneuverability. Also, this reminds me of playing the game called "Red Baron" over a decade ago, which took place during WWI.
The best German fighter, and the most advanced, technically, was the Fokker D-VII. It's performance, on only about 180 hp., was as good as any other fighter. It was the only one that the Allies insisted should be turned over to them at the armistice; all others were destroyed. There were several allied fighters which were comparable in performance to the D-VII, but they used about 400 hp to get it. The Germans, foolishly, built only 6-cyl in-line engines and copies of French rotary engines (as in the Fokker triplane), which were limited by lack of suitable lubricating oil (castor oil).