Do you know about the game The Battle for Wesnoth? No? Well, here is a short introduction from their website:
"The Battle for Wesnoth is an open source, turn-based strategy game with a high fantasy theme. It features both singleplayer and online/hotseat multiplayer combat.
Explore the world of Wesnoth and take part in its many adventures! Embark on a desperate quest to reclaim your rightful throne... Flee the Lich Lords to a new home across the sea... Delve into the darkest depths of the earth to craft a jewel of fire itself... Defend your kingdom against the ravaging hordes of a foul necromancer... Or lead a straggly band of survivors across the blazing sands to confront an unseen evil.
The choice is up to you..."
After playing the game irregularly for almost a year, I finally managed to finish it by playing all the included campaigns. 
And here is the proof (in German):
Have you ever played that game? What are your thoughts about it? Please proceed with caution, though. It's highly addictive.