I once kept seeing the Nitrous bar overlaid in my mind in real life from Ridge Racer 2 for the PSP after playing nothing but Ridge Racer 2 for a month.

After far too much Battlefield 2, I found myself looking at everything and in my mind spotting it for the rest of the team. Enemy Pensioner Spotted!
Oh, and when your text message alert sound is the MGS Codec noise...

I sometimes have epic music from games (Deus Ex, Morrowind...) stuck in my head when I do something epic (ie: running for the bus under the rain).
... ;(

Real life? The EULA sucks on that one.

Yeah, well some of the powerups and extras are nice, but you have to grind like a motherfucker to get them ;-)

I once defended myself against an onslaught of headcrabs while trapped in a vent.

You don't wanna know about the crab onslaught that I had to deal with.

true story.

I though its gonna be "not today Darling, I got a head ache"

Two examples that spring to mind:
After a long day of Quake ][ with some friends, I stood up to go home. I then stood completely still while my mouse hand twitched to the side trying to turn me and my keyboard hand kept trying to press the "forward" key, all to no avail. After a second or two, the motor cortex switched gears and I was able to walk again.
(This one won't make sense unless you've played the game I mention enough to remember deliberately double-hopping through wormholes, which came in clusters.)
Prior to that, I spent a weekend playing Starflight ][: Trade Routes of the Cloud Nebula for something like 30-40 hours straight (no sleep). Finally shut it down and crashed to get some sleep before class. When the alarm went off in the morning, I found myself trying to plot the course of my hand so that I could slide into the wormhole cluster and the right angle to pop out the other side directly into the second stage jump that would take my hand over to the alarm clock to hit the damn snooze button. I think it took me a few minutes before I got close enough to RL to actually get up and turn off the alarm. (It didn't help that I'd apparently slept on one side without moving at all through the night, so my other arm was completely numb)

I often have mornings like this, though it's more often a case of dreams or other routines interfering. I need to push 1 (one!) button to turn off my alarm clock. However, if I've had a long day at work the previous day (I'm a developer by trade) or if I have dreamt something strange, I often find myself trying to do stuff like remembering which stored procedure to run in order to switch off the alarm, and which parameters it takes as input. Or stuff like you talked about, trying to plot the optimal route for my hand from its place at my side to the button on the alarm clock. Sometimes, it takes my girlfriend yelling "Just shut the damned thing off!", before I snap out of it :-/