| For defense, Guard Towers are the best IMO.
If for no other reason than only you will ever know how many you have.
As for offense, it depends on your goal.
Do you want to destroy the enemy's army, or destroy their infrastructure?
Cavaliers for destroying armies, battering rams for destroying infrastructure.
Well, you said *except for* siege engines, so I guess that leaves the rams out.
That having been said, building an army made of only 1 type of unit would be a sure way to fail. You need to be well-rounded; each unit has its own strengths and weaknesses.
I have two modes: wiseass and dumbass. Mode is determined by current blood alcohol level.
Drinking is a sport. In order to be competitive, you must practice on a regular basis. Although you can practice alone, it is much more fun to practice with friends. If you're out of shape and practice too hard, you will regret it the next day.
Life is a disease. It is sexually transmitted and always terminal.