MTW. I am currently playing RTW, but only because of the battle engine. I liked MTW's building roster, unit rosters, capture/ransom of men, governors, generals, rebellions, faction re-emergence, and some of the Battle AI. I didn't like the diplomacy.
I like Romes battle engine (not the battle ai), the strat map a little, and the diplomacy a lot. If the seige bug were fixed I would like it even more. I don't like the temple bonuses, but I can fix those myself.

mfberg