I voted 3, as many here.
However, although i do play games for fun, i do like how history inspired games tend to stimulate my curiosity and i always end up learning quite a bit about the period.
I doubt i would know exactly what was a Janissary had i not played MTW, and it turns out they were so much more than well trained troops, for instance.

Historical accuracy is important, but i will settle for historical believability.

Now gameplay is what kept me away from RTW. Since i play only single player, i found the campaigns bland and dull compared to the diversity i was used to in MTW. One would have more diversity, and more to look forward as time passes.

Making it somewhat similar in Rome might not be historically accurate, but i find it lacking in that regard.