Been playing the single player campaign in Red Faction: Guerrilla. I love how much of a bastard this game lets you be. One of the questions I've been asking since the dawn of the shooter genre was "Why not just blow up the building they're in?" Well Guerrilla is the answer - no tedious room clearing, just obliteration via sledgehammer, remote charges, concrete-devouring nanites, and a rocket launcher. It's also the first game that really gives you the sense that you are in fact instigating a revolution rather than just watching scripted story events. It's great to be pinned down by a squad or two of soldiers then have some random civilian cruise through and run their whole team down with an 18-wheeler yelling "I can do that too!" The mission design is quality too, above and beyond what I'd expect from a sandbox game like this. I just finished one where you have to kill a committee of corporate execs before they get in their cars and run away. First couple times the brute force approach didn't work as one or two slipped through, but the last time I had charges on all their vehicles before attacking. Went through the conference room wall with a sledgehammer, got most of em, car-bombed the escapees.
I'd strongly recommend it, immensely satisfying game packed with creative new ways to blow up the occupiers. The only limit is your imagination (and how many bombs you can carry).