I like to laugh maniacally when I mow down my enemies, be it online or when I'm playing a hack and slash, there's just something about cutting swaths through my enemy's armies that I do so enjoy.
I'm one of those people that picks away at the Giant Crab Boss Monster [TM] with my infinite ammo pea-shooting pistol, saving my Everything Dies cannon just in case there is a Colossal Crab Boss Monster [TM] behind it.
Unless I absolutely need it, you can bet it is going in my backpack and not going to ever get used.
I've gotten a little better about this over time, though, partly because I trust my ability with aforementioned pistol, and because those big guns have gotten more and more fun over time. In ME2 I couldn't help but use the coil gun thing that basically nuked your enemy any time I had a flimsy excuse to do so, it was just so spectacular.
It also tends to be more clear these days where the crescendos of combat are, and when a boss is going to have some stupid second form.
I also do this with potions or special items or anything of that sort that is expendable. I will (or would) restart a section rather than use potions to get past it.
Also, I reload after kills, in addition to reloading when I know my ammo is low. It's a bit like a celebration for me. It's also why I always go for things like the Sleight of Hand perk from CoD4 or quick-reload magazines in Blacklight: Retribution, because I need to be able to do that fast if I don't want to die while celebrating.
I don't know if this exactly counts but I tend to try to struggle through a game even if I don't initially like it just because I absolutely love the boxart. Recent examples of this would be Final Fantasy IV Complete Collection on PSP, Batman Arkham City, and The Last Story.
The Last Story is the exception since I actually DID like that from the get-go, bu the other two i had to play a few hours for them to get good. But they did get good. Really good, even.
I double save at every save point and I save extremely often due to my paranoia that my game is going to freeze.
I don't like leaving doors open in games. I just...don't.
And I'll join the obsessively-reloading crowd. Damn you years of playing CS:S.
And NPC's must be real happy when I play. I just won't let them die. I had such a hard time accepting that it was inevitable in Half Life 2 but you can bet that I kept reloading my Halo save to rescue those marines. Retarded or not, they're still my buddies dammit!
I tilt my head from side to side.
Yes, like a blasted Ewok.
Sometimes, especially if not very engaging, I talk to game itself, trying to discredit it and tell it why I think its shitty.
I always turn off the vibration on my controller. It's strange to me how other people think it's strange to do that.
It's actually quite practical. Your batteries will last so much longer, and besides vibration adds nothing to most games.
Mine is... well I don't want to encourage drug use, but if I happen to have a beer or a joint I will find a scenic or secluded area in the game and just enjoy the view whilst I partake.
I also have a bad habit of getting close to the end of a game and losing all desire to finish it. It's not that I lose interest (if it was, I'd quit a lot sooner) it's more like I don't want the game to end, even if I've done everything else in the game.
In minecraft i always build in odd numbers. e.g my house will be a 7x7x5 cube. my mineshafts are always 3x3.
In first person shooters i have to sitting exacly right with a clear mind in order to play correctly.i need to get a kind of "zen/in the zone" thing happening
in racing games i tend to jerk around the controller like its an actual steering wheel.
in a game that presents stealth choices. i always choose stealth and will obsessively reload saves until i beat it without being detected.
In each new generation of pokemon. i will and have to catch every new pokemon i see. for no reason other then to catch it.