Well, I've been a fan of the C&C series for years (I have every game except for RA3), but it seems from what I've seen and what other people say, it's the game that doesn't love up to it's name. The whole series started worsening as soon as Westwood ceased to exist: doesn't mean that Generals or Tiberium Wars were terrible though.
Back to the topic of RA3 though, I have to be honest and say that I haven't played very much of it. However, the little I played gave me, ermmmm, hard to describe, but just some feeling of something missing.