If you don't care about graphics and just want pure awesomeness out of the gameplay go with Lords of the Realm 2 or the Seven Kingdoms series.
LOTR2 is turn based (so you can go at your own pace) but mixes RTS during battles. Build a castle, Siege a Castle, Dominate the surrounding lands, get crowned King.
As for Seven Kingdoms, I could write a 10 page essay why this is the greatest RTS Strategy game of all time (This is not a biased opinion I've played every Strategy game out there and own and own at most all of them). Graphics lacking, but the gameplay has some serious depth to it that you won't find in any other strategy game and you can customize the difficulty just for you and increase it as you get better. All Trevor Chan games are worth playing. Bjorn Lynne Music is pretty sweet too and adds to the depth.
P.S. if you get the original 7K and find yourself looking at a 'green screen' close and reload the game till it goes away, annoying, but it always goes away eventually after a couple of reloads. I like playing on small and medium maps cause there are lots of islands you can build on and have seperate bases to train troops and build Seats of Power ect. Also I like 7K better than 7K2, but thats just my opinion.