Guild Wars 2, Aion Online, City of Heros (Not as badly), Rift, World of Warcraft, HoN (Not as badly) are CPU dependant titles.
These games will not work as well as they should in cities and heavy-load enviroments, where the age of Phenom really begins to shine. For example, Aion Online dropped down to at times 1-2FPS in cities while things load. On an 8350, the lowest it goes is 40ish. Max FPS is basically the same. This would happen to be on 670s in SLI, no chance its GPU related.
These kinds of games are where new AMD and Intel processors really shine, much more so than most non MMO games. A few other games that suffer greatly from older or weaker CPUS are Planetside 2, FSX, and to a lesser extent, Far Cry 3. There are others, but these are fairly new titles.