Had to add my ditto to this thread. Some of the more interesting playthroughs I've had:
- completely non-lethal - using only tranqs, hand-to-hand, and shock grenades - ended up with 2 kills TOTAL, both from secondary explosions I didn't even cause
- knife guy - tried to make every kill a stealth knife kill, the best I could do after two playthrough attempts was 295
- antisocial - make everyone you meet dislike you, funniest bit was using the "Talk to Madison" action in the Rome safe house - she mutters "****" and Mike mutters back "Bitch", every single time
- grenadier - max kills with gadgets, have to admit I still haven't done too well with this, my best is just under 200, need to try harder
- ghost - minimal interaction with AI on every mission, this is on my list to try, but I just have too much fun killing folks to stick to this playthrough
And again I will say how impressed I am that the game allows so many different approaches to each mission, and they each work without feeling like you are "breaking" the system - they seem to have perks that recognize just about every style of play (the +10 and +25 Endurance perks for nonlethal takedowns was a nice one). Not being forced into any particular playstyle is very refreshing.