What gaming service do you like best?

This is a debate that has been going on for ages. I like both Steam and GFWL and use them both on a regular basis. Personally, push come to shove, I prefer GFWL because of it's messaging features and the look of the client. I love Steam nevertheless but wish you could get a more 'Vista looking skin' for it and I wish you could message people that aren't in your friends list and also message offline users. Please vote and tell me what you like/dislike about these gaming services.