I've written regularly for the Guardian over many years; I've written regular technology and games columns for them at times. A list of all my Guardian pieces is here. Some of my personal favourites are:
Review of Shalom Auslander's novel Hope
Why crowdfunding - the way we funded Zombies, Run! - is a great idea
Interesting research on why Tetris is good for PTSD
Why playing games alone is great
On illegal downloading (and why I sometimes do it)
And from The Times:
A review of the play Posh, and some reflections on Oxford University and men who take a crap in other men's bedrooms.