I'm surprised to see World of Tanks hasn't been reviewed here yet. It's been in open beta since last summer, and goes live tomorrow.
http://wiki.worldoftanks.com/Main_Page
World of Tanks features accurately modeled tanks, pre-WWII to the 1950's, from currently 3 countries...Germany, USA, and Russia. Currently there are about 150 types, broken down into light, medium, heavy, tank destroyer, and self-propelled artillery. Plans call for French, Japanese, and UK tanks soon. Many of the tanks were prototypes that never reached production.
There is a tech tree you advance in as you play battles, so that as you might start in a German Leichttraktor (called the loltractor in game ), you can eventually progress to the Maus, and everything in between.
http://wiki.worldoftanks.com/index.p...=Leichttraktor
http://www.youtube.com/watch?v=Vvw0tE6us7A
There are 10 tiers of tanks in each country's tech tree, and a battle of 15 players per side is balanced with tier overlap, ie, a tier 5 tank might find itself matched with a tier 7. Depending on which side of this equation you find yourself is a big factor whether you will survive the battle victorious or wind up a burning hulk.
Each battle is quickly generated, I've never had to wait more than 30 seconds, and the battle itself lasts a maximum of 15 minutes (a draw) unless one side destroys all of the enemy's tanks or captures a flag and holds it for a brief period.
There are currently about 15 maps, approximately 1 square kilometer, that are randomly played on, but shortly after release there will be 2 more, and a clan war feature using a zoned map of Europe. Later it will be expanded to include other theaters.
The battles themselves utilize a third person view, but when engaging you can zoom into a sniper view very quickly for precise aiming of your gun. Terrain effects are present, and the environment is somewhat destructable (ie, smaller buildings can be destroyed, trees knocked down, etc.).
The is basically a free to play game, and download, but most players buy "gold" from Wargaming to play "premium" which increases the "experience" and "credits" you earn from a battle by 50%. Experience is used to research tank modification upgrades (better engine, bigger gun, etc) and then these items are purchased and mounted on the tank with credits. When you've researched the necessary mods for a tank you can then research and purchase the next tier tank, eg upgrading from a PzIII to a PzIV. Better tanks have a better chance of victory.
The price of a month's worth of "premium" play is roughly $10 US, although I cannot stress strongly enough that the game is totally playable and enjoyable without paying anything at all.
The graphics and sound is very immersive, and although I just started playing 2 weeks ago, I've played over 800 battles and got to my PzVI (Tiger) yesterday.
You can "platoon" (group) with up to 3 tanks per platoon, if at least one is a premium account. There are also company sized battles, although I've not participated in any of those yet.
Many people join clans, which will be necessary to participate in the soon to be released clan war feature I mentioned earlier. I just joined the largest clan, Angels of Death, which recently won a tier 8 tournament and will be going to Moscow ( home to the development company, Wargaming)to compete in the finals.
If you've any interest at all in WWII armored warfare I would highly recommend this game.
This is a pretty nice video of a typical battle...http://www.youtube.com/watch?v=LBUIK...eature=related