http://www.frozensynapse.com/

Frozen Synapse is a "simultaneous turn" tactical game very similar to playing original Rainbow Six but without leaving the commander mode. (though units are limited to just 1 weapon - shotgun/MG/grenade/rocket launcher). It's a blast in SP and MP.

Be warned: You must play the tutorial to understand what you're doing.

Not very expensive either, basically 18 euros for 2 copies:
http://store.steampowered.com/app/98200/

The game also has an export to youtube feature, so there's lots of match results movies like this one:
http://www.youtube.com/watch?v=VYRUHsXPhSw&feature=related

To the price:
If you buy it on their web site and SELECT USA as a country you will be charged in Dollars,
which is after translation to Euros about 15 €.
You will then receive a registration code which lets you activate the game at STEAM.


The game is awesome BTW.

Sneaky