D&D is clearly a simulation, just not of the real world, but it's a fairly accurate (although not detailed) simulation of the (high) fantasy genre, I have no problem recreating scenes from books/movies/shows using the ruleset.
For a more real-world simulation, indeed Runequest is what I've found the closest to real-world combat (in particular the rules about Strike Ranks, reach, engagement, etc.), and a friend of mine who rose to be the King of Britain through the SCA (and combat) was of this opinion as well.