I also vote for M2TWK.
played all series except the first shogun ,and i say NTW is the best!
I like them all, but NTW is the best so far.
As odd as it seems I like S:TW even if it's like 10 years old(remember that back then it was something big!!) M2:TW(just M2:TW and TA:TW) and so and so ETW.
I just had to say it! Medieval 2 Total War is by far and still the best of the total war series. The Modding community has made this game my favorite. It's diversity with mods spanning from SS to Kgcm to Third Age and BC has brought a great deal of freshness to it and it still brings through their updates and the making of new mods such as the in progress Warcraft III mod, and others!
Medieval 2 and Kingdoms ... also Shogun 2
M2TW absolutely! It's just amazing.
Rome Total War
Brilliant game and so easy to fiddle with
Militia Hoplites - best unit
Rome Total War/Barbarian Invasion
When modding it many people get the chance to show their creativity. (even me )