Monster Energy all the way here. For sure it's the best kind of drink to play video games with. I don't like Red Bull though I think it's nasty but a good green monster would set me straight for some game playing any day.
I remember some of the gamer friends that I know used to take the red bull too. It was good for them at that time but also it has lead to some of the health issues. So regular consumption is definitely good for the health. That's what people have to watch out for.
It may sound strange, but drinking water while I game back then really worked for me as I never had headaches no matter how long that I game. What is necessary also is that I enjoy some nice time drinking water with friends when I game as well.