I drink beer and play the Turbo every weekend. It's a little ritual I have. My wife hates it because I stay up late and come to bed early in the morning. Of course, without a RedBull or Rockstar this whole concept falls apart because the alcohol makes you tired and you end up nodding off.
You see, there is a very defined "zone" you can get into after a couple beers (2 and 1/2, maybe 3) where your confidence is boosted just enough so that your playing ability actually improves. It's a really fine line, though. After 3 or 4 beers, the alcohol is definitely a detriment as your reflexes and reaction time go down the shitter. I've gotten some of my best scores of my life while playing in this "zone."
When I was younger, maybe 10 years ago or so, I used to play stoned and high all the time. I tried playing TurboGrafx (don't remember what game) on mushrooms once but I actually had to turn the game off because I was more interested in what was going on in my room.
I've found most substances are pretty detrimental to one's playing ability for one reason or another. Either you can't concentrate on the game or your reflexes are shot. Although I will admit I have never been as absorbed into games as I was when I'd play Space Harrier stoned. I think the first time I actually beat the game I was ripped out of my head. Now
that's an experience
everyone should have!
Popping a couple Vicodin and playing is always good for some fun, too.