IMO the most over rated games this generation are mainly PS3 exclusives: Resistance 2(fell short of the high sales expectations, RFOM was bundled heavily), Killzone 2(below high sales expectations), Motorstorm: Pacific Rift(Fell short of the high sales of the original game in the series which was bundled heavily with PS3) Little Big Planet(Around half of the two million copies sold were bundled with PS3), Metal Gear Solid 4: Guns of the Patriots (failed to break 5 million sales and touted as being the huge PS3 hardware seller game/ PS3 saviour), *Halo 3 (XBox 360), **GTA IV (multi-platform: PS3/X360/PC) and ***Assassins Creed (multi-platform: PS3/X360/PC).
PS3 exclusives = so much hype but they could not save the PS3. PS3 is such a heavily priced game console, people need to justify their purchase.
*Halo 3 was a good game but not a great game. It failed to live up to its lofty high expectations and was just an upgraded version of Halo 2 but with a better single player campaign and online experience in Halo 3 was a huge improvement upon Halo 2.
**GTA IV well it met high sales expectations but the near perfect critical reviews were undeserved for the game. I. along with many other gamers were disappointed with the game.
***Assassins Creed was brilliant for the first hour or two you played it but it soon became boring and repetitive and felt more like a chore than an enjoyment to play the game.