Does video game facilitated roleplaying actually exist?

I've had a precious few extended jags in World of Warcraft over the past few weeks as we prepare for our move, and as I played the game by myself I found that it was pretty easy to engage in the storyline. A few times, in fact, I actually felt invested that my character would want to actually help the world and it mattered.

Then I got the opportunity to run through an instance of Ragefire Chasm with some more experienced players. I understand that each person plays the game in their own way, and often the raids are about efficiency. My experience of actually engaging in the storyline was pretty well shattered by "talk to this guy, get this quest, then get back down there and more killing."

So I ask you, loyal readers... has anyone had a satisfactory roleplay experience using a packaged video game (such as WoW, Neverwinter, etc) as a medium? Granted, we weren't trying to replicate D&D style roleplay in our World of Warcraft efforts, but it was a bit amazing how quickly things devolved into hack and slash, efficiency gaming once a group came into the mix.

So let's hear it from you... does video game facilitated roleplay actually exist? Can it be done?