Far Cry 3 is absolutely awesome. Maybe the GOTY last year.
It lasts a lot longer than your average shooter... like 20-30 hours. But dont expect RPG level of gametime. There are two huge islands to explore and you will want to. But after you finish exploring them theres not much else.
I loved it though, and will definitely replay it again at some point (I usually never replay games). Awesome gameplay, decent story which allows for great missions, fantastic villains and cutscene style. But most of all the island is awesome. Watching the animals interact randomly with each other is awesome. Randomly seeing an NPC get snagged at the side of a river by a crocodile... or hearing explosions in the distance, running in and finding everyone dead and 3 komodo dragons feasting on their corpses is just beautiful.