I like the Nieuport series of fighters the best (11,17,24). I started sim flying back in the original RB in the early 90s and the Nieuports offered the best balance of features: light, agile, responsive, fast for their time, and the handling is instinctive (there's no heaviness in the controls). My only complaint is that they're not terribly well-armed, apart from the optional extra gun on the N.24 (though not all had it). But that said, if you get close and work hard, you can score well with them. The N.11 is a joy to fly, but as a pure fighter, the N.17 is superior due to its better gun system in the French example (British often retained the over-wing Lewis). The N.24 is a great plane as well-- basically just an improved N.17. I'd love to see an N.24 in OFF, to resurrect its flying days from RB3d. I'm more confident in the N.17 than any other aircraft in OFF, even later planes like the Spads.
The Sopwith Pup I find to be the British-made cousin to the Nieuports: light and agile, with intuitive handling once you get used to the rotary system. It's a great little flying craft as well.