The original Jagged Alliance was a turn-based tactical combat sim in a similar vein to X-Com. There's going to be a brand new entry in the series, called Jagged Alliance: Back in Action. It's out on October 18.
Instead of spinning off in a new direction from its predecessor, like XCOM, Back in Action is a faithful modern remake of the old game, with upgraded visuals. You'll find more information on the official Jagged Alliance: Back in Action site. There's a trailer, too. It's entirely in German, but still provides a good overview of how the game works.