There are best games of the genre like MOM of course, but, there are only 3 best overall AI and AI adjustment games. Those are:
AOW:origional (you could set each ai to a different type of play from passive, to aggressive, to torch n burn to defensive and offensive or you could set each one to random and the game would pick a play pattern for them every game. Too bad the AI in AOW:O liked to build too many siege engines and run up and down the roads back n forth.
HOMM II: This is the best of that series because you could set EACH AI from Dunce to Expert and also set a level of difficulty besides. Later games of the series from HOMM III onward you are only able to set the difficulty.
Warlords III: This is another one you could set the AI play type from aggressive to offensive or torch n burn etc. The Warlords series has the best AI of all of them actually. The bad thing about the Warlords AI though is it really never protected its Heroes/Leader units and many times would march around the map with them solo. I've seen it have the clear advantage and could have won the game because it had built up a good hereo only to seperate it from its dragon stack to be destroyed by me or some ruin by itself.
While Elemental does have different difficulty settings for each individual AI as well as an overall difficulty setting it doesn't provide to set each individual ai a characteristic settig like aggressive, passive, offensive, defensive, torch n burn. I'd really like to see those elements in this game. The torch n burn ai can be the most devestating as they raze everything in their path.