When I write, I like to have rain. If it’s a beautiful sunny day, I still like to pretend there’s rain. I use http://www.rainymood.com/ to get that happening.
Then I’ll have some music on. I can’t write to anything with lyrics, I find it too distracting. So I go for classical, or, more often lately, movie soundtracks.
I tailor playlists to whatever it is I’m writing. My space western short stories have all been written to this one, and it’s proved helpful for other genres as well, lending a little bit of edge to my characters which I’m diggin’.
So, that’s that. Noisy neighbours, traffic, the trains rolling by a hundred feet from where I sit, all fade away as I am pulled into focus by rain and music.
H.G. Bells 
I love to hit up some phat chiptunes while I’m working on game stuff 😀