The MOST replay value for me. Living graphics, in-depth strategic play, immersive tactical battles, mods aplenty.
The graphics contained WOW factor from the first time I played it and still keep me visually piqued.
I find the combination of strategic gameplay and battlefield tactics wonderfully immersive. This is one game that really sucks me into that void where time passes unknowingly (when you suddenly realise you've been playing for hours and it's now 3am).
I love games that mentally challenge and will still have me playing years later. This game has become my benchmark and I have yet to find another game that offers anywhere near this much gameplaying value.