There are a number of games which blend strategy with first-person action to some extent.
Hostile Waters and Battlezone have been mentioned. Battlezone 2 continues to receive [url=http://www.visi.com/~nathan/bz2/bz2_13.html]unofficial patches[/url], incidentally.
Uprising and its sequel were touched upon already. They were released at a similar time to the Battlezones, but the gameplay is rather different again. I've not played Uprising 2, but I'm quite fond of the first one. It takes a bit of getting used to -- you can call in support units from your tank, but you can't direct them around, which seems weird at first -- but it's a really nice game IMO. How does Uprising 2 fail on your machine, lowyhong?
And then there's Urban Assault, which hasn't been mentioned. Trailer here:
http://www.youtube.com/watch?v=dgAnpPxu1z4 Sadly I've also not played this one, but I've heard some good things about it.