@ Chong Li ... play Fall From Heaven II, a mod for CIV IV BTS. Its replayability, its unique tech tree .... definitely a war-focused game, tho I do admit some can eventually build guns or cannons but other than being "mass producable" their not that good, and come far too late to be "winners".
If you wan't to find interesting research (although some people have certain rush strategies depending on map size and game speed), I would suggest it ... if nothing else than that the Civs are so different, its rare for you to want the same system over n over again. For instance, Elves can build in trees, so going mysticism and education is the best investment (and going FOL religion) while dwarves and vampires do well with large populations (in different ways) so Aristocracy + farming is the best... AKA Calendar and Code of Laws beeline.
Meanwhile, the Kuriotates have the biggest cities, but their cottages (education) also have the highest potential ... so while Aristofarming could work, a well protected cottage industry could be so much more.
It just goes on and on. That was just mentioning the "commerce" goals for tech ... saying nothing about the warfare which is 80% of the game or so.