The closest thing I've seen to "Advanced Squad Leader" for the PC.
The game puts you in command of a few platoons of infantry, armor, AT-guns, mortars, off-board artillery, and other goodies. The game simulates a command structure by allowing you (indeed, requiring you) to give orders to a platoon leader. The other units in that platoon then follow the general instructions of their commanding officer, although you can step in and micromanage the sub-units if you like. This mechanic is reminiscent of the excellent command-and-control system in the "Airborne Assault" games, also published by Matrix, such as "Conquest of the Aegean." In fact, in some ways, this game is a turn-based, tactical-level version of the Airborne Assault series.
The game ships with a particularly interesting campaign system, including random campaigns and a random battle generator. I haven't had time to sample much of this yet, as I'm still working on one of the four or five pre-set campaigns that ship with the game. They are great fun -- and quite a challenge. This game will make you think.
The AI is surpisingly good for a game of this genre. Or maybe I'm surprisingly bad!
You probably won't buy this game for the graphics; even at the highest settings, they're not particularly flashy. The infantry animations aren't the greatest, either. But the visuals get the job done. Interestingly, the designers have chosen to portray your units at a realistic scale, which can make it a tad hard to see and select them. Fortunately, you can toggle on unit icons to help you see things.
Some people have complained about the maps, which are limited to a square kilometer or so (I think), but I find they're plenty big, and they have a realistic feel. In fact, I think they're a real strong point in the game.
All in all, this is a terrific wargame. My only caveat is that it will probably appeal most to serious grognards. Still, anyone who has enjoyed turn-based strategy games for the PC should check out this title. If you like to think your way through combat, you should give this one a look.