Not sure if anyone recommended the Anno series yet (didn't see it in the OP list), but for those interested in the RTS type of games this is a must try. Their approach is aimed more towards the logistics and city building aspects, rather than the military and conquest parts (although these aspects are present in the game). I love their games because they are so complex and theme-oriented (for example their latest game portrais the 19th century-early 20th century era) with lots of possibilites to tackle each and every aspect of the game.