I'm a big fan* of Battlefield 2.
With two amazing children, a bustling, demanding business, and a professional career, it's very difficult to find time to play, but I really try to get a game in every now and then to settle the brain a bit (I find gaming enormously beneficial when doing demanding software projects). The game is visually gorgeous, and in many ways it's the game I (and countless other gamers) "invented" in our minds years ago - "Imagine if there were helicopters and planes and boats and tanks, and different people had different roles. Boy, I'd love to be the helicopter guy shuttling people back and forth!".
In many ways, albeit at a much more arcadish level (e.g. less serious than real simulators), BF2 is a completion of the vision started with Falcon 4 (F4) and its dream Electronic Battlefield. F4 was a remarkable game far before its time, and it actually looks pretty good even on modern hardware (and it can still push modern hardware to their limits). The vision with F4 was much more vehicle specific though, and while many players would exist and battle in the same world, each would be using a specialized, extremely realistic client conforming to their specific interest. Not sure how that'd work if you wanted to eject and then climb into a tank...maybe you'd shut down the client and restart in the tank simulator.
We need a game with the gameplay of BF2, the flight realism of F4, and the troop realism of Operation Flashpoint.
* - BF2, like all large software products, does have numerous problems. For instance the surface to air missiles are infuriating: Not only do they have a ridiculously low hit rate against the enemy, letting enemy aircraft fly around with impunity, but they have an amazingly good (or rather bad) hit rate against friendlies. If you shoot off some SAMs at an enemy aircraft, you can be sure that they'll miss, but that they'll fly off and manage to find a friendly helicopter or aircraft somewhere else on the map.