Reasonable on 29 October 2010
Steam easily for me.
Best deals and a simply huge range of quality titles now, plus clear links to reviews, trailers, specifications, etc.
Auto-update of titles.
Ability to use your games on up to 5 PCs and have saves, etc. stored on Steam cloud.
Easiest to navigate (okay so using a mouse in a shopping environment is probably an advantage but hey) and most user friendly interface.
Live and PSN are pretty good stores on the console side, but I find Steam from a pure shopping/access point of view way ahead.
Try to be reasonable... its easier than you think...
