I've got to say, HMV do have a really good selection of games (at least if the Cambridge branch is representative). Obviously they don't do much in the PC category but they had quite a few shelves of 360 and PS3 titles in addition to the expected chart games display. And while their prices won't beat ASDA or online stores, more often than not they were better than GAME's.
One of my biggest surprises: Finding Shiren the Wanderer DS on launch day in HMV. Genuinely surprised that they bought in such a niche title.
But then... they'll stock fairly niche DVDs and music, so why not games?