Fore more realism I'd check out Operation Flashpoint. However i came to the conclusion that if realism makes the game less fun, why bother. If you really want something that realistic, go sign up to the army. Your d-pad will be replaced with much more accurate M4. Your fictional boot camp which hardly teaches you about being a real soldier will be replaced by a real boot camp. Lastly, and most luckily you won't have to get annoyed at regenerating heath as when you get shot, you will hurt Unless your wolverine, in which case thats awesome.
I actually prefer the idea of being the one man army, for me it makes me less annoyed at idiotic AI. Take MW2 for example, when playing as a regular US soldier you ever realised your taking on a mountain of troops as one man yourself, however on Halo games that makes sense... your a super soldier. Sadly i don't think a more realistic game will solve that, as AI isn't that smart and they will always target you before their damned AI counterparts on your side. It's a damned conspiracy.
I actually prefer the idea of being the one man army, for me it makes me less annoyed at idiotic AI. Take MW2 for example, when playing as a regular US soldier you ever realised your taking on a mountain of troops as one man yourself, however on Halo games that makes sense... your a super soldier. Sadly i don't think a more realistic game will solve that, as AI isn't that smart and they will always target you before their damned AI counterparts on your side. It's a damned conspiracy.