If you derive even the slightest bit of pleasure from blowing stuff up in videogames, you owe it to yourself to check out Red Faction Guerrilla.
Basically, this is a GTA-style sandbox game set on Mars, where some naughty tyrants are exploiting the great unwashed, who in turn are not particularly happy about said exploitation.
Which is all well and good, but what this game really boils down to is an open license to level buildings in any way you see fit, whether that be via sledgehammer, remote charge, rocket launcher, or vaporising laser-gun thingy. And no matter how many buildings you level, it JUST NEVER GETS OLD.
The main campaign storyline has a good mix of missions, including driving, firefights and demolitions, but there's just as much fun to be had cruising around Mars and partaking in the various side missions. Especially those that involve – you guessed it – blowing stuff up.
The main story will probably take you 15 hours or so to finish, but add on the many side missions and the multiplayer component and there's more than enough to keep you occupied for ages.
Overall, Red Faction Guerrilla is a helluva lot of fun. Not the greatest storyline of all time, but it doesn't really matter when the fun factor is this high.