Danger Closer (DC) as suggested over at rpg.net when I was hunting down other spy games to use for Alpha Protocol. DC is a free spy game written by Rob Justice and is well worth the download and read.
In DC, Rob brings up John Wick's theory on the rolling the dice question. Rob explains that players only roll the dice when there's an inherent risk involved and the character wants to acheive something more than his or her obvious means could acheive.
Keep reading, I eventually get to the point of my lil' essay here!
So I like this idea of risk and not making every single step of an action hinge on the dice results, but I do have my own philosophy (in which, I'm sure, I'm not alone). Since RPG's serve as a collaborative story telling device by their very nature, the only real thing player and GM can do in a game is to determine who has control over the story. It's a constant negotiation between what the GM wants and what the player wants to have happen. A lot of times this is actually the same things. I know as GM I've wanted my players to be really successful at doing something truly amazing because it makes the story cooler.
However, the GM does have a responsibility to make failure an option, otherwise there won't be any glory in the success. To this extent (and for those times when the GM thinks a player should fail at something), when do we roll? The player rolls when he wants to impact the story. Universalis is a GM-less game. Each player is given resources that he or she can spend to create elements of the story. It's a great (and I believe one of the first) GM-less rule sets in that it gives everyone the power to impact the story equally. I tend to pull that lesson back the GM-centric/traditional game to say that the way a player creates his character, focusing on stealthy thievery, strong-arm brute, or smooth-talking face determines how a player wants his character to impact the story.
Whew! That went on longer than I meant it, and if I ever do produce an RPG, you can beat I'll probably steal wholesale from myself here to describe why a characters rolls a d8 or whatever!