Hmmm... 1) Half-Life 2 (PC)
2) Battle for Middle Earth 1 & 2 (PC)
3)LOTR: The Third Age (X-Box)
4) Battlestar Galactica (X-Box)
5) James Bond: From Russia With Love (X-Box)

These are my current top 5, though after seeing Gears of War on the 360, should I ever get a 360, one of the above may be surplanted.

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SILENT DUSTY

"...but for a soldier his duty is plain. He is to obey the orders of all those placed over him and whip the enemy wherever he meets him."
- General Ulysses S. Grant