I've only completed one of the Jagged Alliance games, but it just so happens to be widely considered the series' peak. Jagged Alliance 2 is an incredible strategy game, where you recruit a selection of mercenaries to overthrow a despotic leader of a tiny country. The mercenaries are all characters in their own right, with RPG-style skill progression and their own personalities. Take the wrong collection of mercs with you, and they'll bicker and fight. The right ones can make the game endlessly easier.
I'll no doubt cover the game in this blog, because it does make for a great game to talk about. It also has a still-active modding community, and the 1.13 patch adds a massive amount of depth to an already great game. It's charm lies in the different ways you can approach the game, from the more stealthy to the full on Schwarzenegger. But enough about the old game...