Hehehe... I have all of them & all the DLC up to Napoleon. I'll gladly challenge you at anything! Love that series more than any other.
If you're playing RTW, check out Rome: Total Realism, at
http://www.rometotalrealism.org/ Try RTR 6 Platinum before you try RTR 7.
Yeah, M2TW multiplayer stinks (If you can get it to work). RTW's multiplayer is rock-solid, but it isn't as cool as the later ones.
Empire's multiplayer is plagued by the game's shortcomings, but it's multiplayer is good as well, introducing new features / battle types. Napoleon's multiplayer is the best out of the ones I have. It's rock solid, all the features & battle types, plus multiplayer campaigns. They incorporated everything everyone has been dreaming about since the RTW days.