I spent about two years totally devoted to it, it's especially good online because the AI isn't too smart, but human opponents can be extremely devious. It has a lot of similarities to poker, in the sense that it involves a lot of evaluation of statistical probabilities. Like poker, a great army can still be wiped out if your opponent has a lot of luck!
With fifteen available races and lots of different units for each race, it is also quite a complex game, which for me leads to long-term satisfaction. There are orcs, goblins, elves, dwarves, lots of magic spells, so it's very Lord of the Rings in nature. Let me know if you ever want to try it out online!
__________________
"You shouldn't let the strength of your hand affect the size of your raise. A tough poker game is like real estate.
The three most important factors in deciding how much to raise are: Location, location, location."
Chris Ferguson