Stronghold, that brings back some memories. I tried it online but used to get slaughtered. I loved the comic like character voices. I can still hear them reverberating around my head !
"Yes m'lord"
and the sound of the toplling wood when a cutter came back to the store or the oxen having it's throat cut !
The Total War games were great too although, I was rubbish online and lost nearly every game I played. Two allies went ballistic at me in one game when they sacrificed their armies byt charging down a hillside so I could win. They said that they would not actually have been able to work out how to lose like I did !

I played the one player Rome Total War and finished it but it always crashed after what I assumed was the last battle so I never got to see what happened at the end. I preferred Viking Invasion to Rome, I thought Rome was a little too easy to manipulate, Viking Invasion was rock hard when you got to a certain date.
The last good tactical wargame I played was Company of Heroes, that's pretty cool but, once again, rock hard against online opponents so I stuck with the single player game.
The last game I played was Battlefield 2, several months ago now. I used to play it almost every day for a while. It was VERY addictive. That's actually the reason I never bought World of Warcraft because my friend lost his real life for the best part of a year and I didn't want that happening to me !