Katman: There are a few good flying WWI bipes. The Fokker DVII ,The Sopwith Pup,The Bristol Scout D,The Se5a & The Albatros all exhibit good flight characteristics, I have flown all except the Albatros, but I have seen it fly. I am currently bulding a 76" Albatros DIII.
In sport planes, The Sig Hog bipe, Cunningham's Lazy Ace, The Aeromaster(in any size) and my personal favorite, The Phaeton bipe all fly well.
These are by no means the only good flying bipes, just the ones I have experience with.
Happy landings Tony