If the Winter weather is getting you down or you need to blow off some steam after your first day back at work, then you won't go too far wrong snapping up the bargain that is Far Cry 2 for the PC. Building nicely on the open-world environment of the original, the sequel offers hours and hours of explosive action, in an even larger open-world coupled to an open-ended storyline. So you can go anywhere and do anything you want. At just £3.99 including postage from The Game Collection, it's a few quid cheaper than the next best online price.
If you love FPSs then Far Cry 2 is a must play. However, its open-ended story isn't perfect, it causes as many problems as it's supposed to cure, but it does remove the self-imposed 'corridor effect' many shooters suffer from and results in a beautiful open-world drenched in African sunshine. You should find yourself blasting through an avalanche of explosions and in vehicles of all design including boats and hang gliders, but if you do get stuck don't miss the walkthroughs at GameFAQs.