Have you ever wanted to play the game windowed?
There is also a widescreen mod thats really good. Give you a really good advantage when you can see the majority of the map in one screen.
I liked the whole series and Empire Earth as well... AoE 2 + TC was the best in my opinion... clean visuals, nice history details and pretty balanced AFAIR (Except for the Paladins).
First off the bat I found the heavy horesmen to be generally useless. The resources needed to build them could be spent to train more infantry or to rush faster. Not to mention pikemen.
Now a Horse Archer rush coupled with A couple Light Horsemen to cut down villager populations and stray infantry was a simple easy tactic.
Basically I would pick my civ based on how we we're going to play.
Goths in the low resource dark ages and fedual starts for an easy raids. Huns/Mongols for a high resource fedual/castle age start since the horsearchers could be churned out so fast it wasn't funny.
Finally the Aztec/Goths in the Imperial Ages when defences no longer important since trebs. exist, Aztecs for an offensive player who fields the large armies (infantry to tangle up the troops, monks to convert them) and goths when they're turtling in (just keep sending the meat shields at the walls, protect your trebs.)
I even bought a video card to play AoE III, but for some reason it didn't grow on me as AoE II did... IIRC the whole colonial thing (with things being sent from Europe), broke the game...
I didn't like the campagin of AoE3 at all. It was just jibberish with no historical basis at all. I know the age wasn't as action packed as the medieval and ancient times and were mostly devoted to genociding troublesome natives but still.