Jagged Alliance 2 is a great game with lots of depth. Fun for any RPG, RTS, or TBS fan.
You start with a budget and a pool of a large number of mercenaries preparing to engage in covert warfare on the island of Arulco. The story is this, an evil dictator has de-throned the rightful monarch (Monarchy: A political system of hereditary rule, not like an Elven King) and he has hired you and your men to take back his country.
This is when the game gets good. You begin with the option of creating a custom mercenary and then assembling a team of soldiers, medics, and mechanics. Your team is created by hiring people from a mercenary pool. Each individual is unique and offers something different in terms of experience and skills, this is the heart of the RPG game in Jagged. As you play with these characters you will see them improve their skills and attributes and offer you more bang for the buck. You can also spend time training your men when there is no action, which takes more time.
Your objective is to conquer all of the cities in Arulco and free the people from the "Queen's" evil tyranny. As you take control of more territory you'll see greater income in your budget which you can spend on soldiers, weapons, armor, and equipment. Additionally, you sometimes unlock new storyline elements bringing new objectives or new people.
The game takes some time to beat just because of the island's size and scale, its not something you beat in one day. Secondly, replayability is high because of the uniqueness of all the characters.
My only dislike is that the game limits you to 20 mercenaries total. While it is reasonable to maintain a small mercenary feel it rather hampers the game because there are far more then 20 mercenaries total to recruit from and it sucks to miss out on characters because they are all so unique and have something to offer.
Lastly, you can find some excellent modifications for the game which almost act as a uber-patch or expansion pack. Try: http://ja2v113.schtuff.com/features
Conclusion? Jagged Alliance 2 is an addictive and excellent game that everyone who calls themselves a game needs to play.