Mass Effect features some of the most vital elements found in traditional adventure games, including story and characterization.
Click the image for a video clip showing this.
Just wanted to pop in and say that, wow, this is EXACTLY the same discussion I was having with other AG friends 5 or 6 years ago!!
I had even written a 4 part essay about this back in 2005 over at Adventure Developers:
The Cold Hotspot | Adventure Developers
Nothing's changed, really. And now it's several years since I wrote it, I don't expect it to ever change. As long as the niche crowd is happy with the genre's status quo, well, they're happy. But some of us here can also find adventure game elements - and many necessary progressions and innovations - in other games not arbitrarily categorized as adventure games.
But with me, I've moved on. Many of the most important and characteristic qualities of the bona fide adventure game have made their way into such highly impressive, dynamically progressive, inventive, commercially successful, and critically acclaimed games like
Mass Effect (writing, story, dialogue, characterization, exploration),
Portal (puzzles),
Fable II (story, exploration),
Okami (puzzles, exploration), and others (click each title for a respective brief clips of gameplay or cinematic).