Prince of Persia (2008) for sure. One of the biggest bummers this gen that Ubisoft completely threw out this game in the cold, despite doing OK sales wise.
I don't feel it has a strong following either, since it's not really a proper PoP game for most fans. It wasn't really that challenging and it strayed far from the puzzle platform elements of previous games. In the end, it was mostly remembered for it's DLC epilogue that sparked a debate regarding important story stuff as DLC.
Which is a shame, because I will fondly remember everything else about this game. Sorry Mirror's Edge, I like you a whole lot and I look forward to the sequel, but parkour should be third-perspective and stringing together a 10 minute seamless combination in Prince of Persia was and still is one of my favorite moments from this gen.