Universe At War for PC. Runs on both Win XP or Vista. (cheaper than the Amazon deal posted a while ago, and also no catch where you have to subscribe to Amazon Prime!!!)
(Pls take it easy if i've made any errors. First time adding links, and a pic and vouchers :)
£4.73 less 10% voucher = £4.25 delivered
Good, and new game.
PC Gamer gave it 85%.
IGN review "Impressive 8.0" http://pc.ign.com/articles/841/841719p3.html
Developed by Petroglyph, this combat-intensive real-time strategy game enlists players in an epic struggle to prevent total alien domination of planet Earth. Universe at War: Earth Assault is set in the near-future when multiple factions from across the galaxy have come to Earth to wage epic warfare. Containing numerous features and customization options never-before-seen in the RTS genre, Universe at War: Earth Assault creates an exceptional strategy experience for single-player and especially multiplayer battles.