aramis erak
Legend
Seconded,
HERO is most famous for Champions but is is as much a generic system as its cousin GURPS.
HM
Moreso, really.
GURPS builds around a basis of a strongly accurate medieval combat simulation, based upon Steve having done a lot of research with SCA and other HEMA fighters. That pushes certain elements in certain fairly realistic directions.
Hero, meanwhile, is less accurate at melee, but more flexible overall, since it's not got hardcore simulation in the core rules.
