Where to start?
I have been playing this game nearly a year and it still holds my attention.
Its like peeling a onion theres always some new strategy to discover, a new hero description to read, new nations to play (thanks to the patches and modders), a new map to try.
There are 60+ nations (I have honestly lost count) in just the basic game. Alot are very different from each another and even the same nation can be played many ways.
You also have an excellent MP community and the game is pretty easy to play with your friends locally via a server, so you can play from the comfort of your own home and laugh about it when you meet up in the pub.
Replayability, depth, bags of strategy and large roleplaying elements. Illwinter a team of just 2 men put the bigger software houses to shame.