I can't believe this is allowed, but since no one is stopping it I want to pimp 2e and totally burn down 3e... if 4e was still in the running it would make it a hard choice, but with it already sniped 2e is the best
Original Dungeons & Dragons (incl. BECMI) 21
Advanced Dungeons & Dragons (1e, 2e) 20+1=21
Dungeons & Dragons 3.X 16-3=13
Dungeons & Dragons 5th edition 23