Sins of the Solar Empire is my current favorite strategy game, although its quite a bit different from the games you mentioned.
The Combat Mission series has some great turn based strategy games, although it's not quite the same as any other strategy game. Basically you tell each unit what you want them to do, then they all move together...at the same time as the opposing team. You then watch to see how the turn unfolds.
Another strategy game I was addicted to for a while is the Heroes of Might and Magic series, although once again it's very different from the games you mentioned.
Sorry, I guess I'm not much help in finding exactly what your looking for

Although years ago I did love the game Iron Storm on the Saturn, which is pretty much exactly what your looking for (Advance Wars without the cartoony graphics), but it's been so long since I played it and you probably don't have a Saturn, so it's kind of hard to recommend it
