I have clocked over 1000 hours on this game on the old retail DVD version. And all i can say is this is the best Total War game CA has released - and will probably ever release. Shogun and later games have their good sides but this one is still the best. Kingdoms expansion adds some 200-500 hours more of gameplay should you run out. Stainless Steel and some other unit expansion mods adds some hundreds more.
Graphics are getting old and the good ol' AI is not that splendid. Not even with mods - but this game along with it's older brother in arms Rome Total War got things right on some things that CA persistently cannot reproduce anymore: pure fun, paper rock scissors -type of strategy that enables exciting and interesting meta-campaigns. (who cares about official campaign goals - these games are always more or less open ended). And lets not forget those exciting long battles.
Later games brought more crashing and complexity and lost something on the road. Fun and entertainment value being the first ones who took a fatal trebuchet cow carcass shot to the neck.