Not that we're necessarily surprised by Sonic CD taking the number-one spot on December's PSN charts, but it's always a little sobering when the classics of yesteryear outsell brand-new titles like Trine 2. Nostalgia is a powerful thing, friends.

Well, the fact that Sonic CD is arguably the best 2D Sonic game of all time probably has something to do with it too, but we all know most of us bought it just to hear Sonic Boom again. Hop past the break for the full list of December's best-selling PSN titles.