Far Cry 2 (Xbox 360, 2008)

It's a lot different than most shooters in that there's no direct linear progression path. The game sets you as a mercenary and you really end up feeling like one, with multiple ways to complete your objectives based on your tastes.

Despite being an open-ended game the story missions are more or less the same (there's a random factor that changes things up slightly) and the story has interesting ideas dealing with politics and moral choices, but the execution is as you can expect of a shooter (i.e. the execution sucks). That doesn't make it a bad story, but there are some parts that could've been fleshed out more.

Music is fitting for the environment, but gets old fast.

This is a long game, it's length rivals some of the western open-ended role-playing games, definitely longer than most shooters, difficulty and AI are varied. AI isn't particularly spot on, but they do a good job at trying to flank you and hiding (it's very easy to hide given the setting) and the game is definitely challenging on higher difficulties.

Overall it's a great game, although it takes a slight amount of patience. Think GTA in Africa except there's no cops and more or less everyone wants to kill you except for a handful of people.