The real answer is Blur. Was hailed as "The COD of racing", had a HUGE (and semi-controversial) advertising campaign, then it sold 30k (combined) it's first NPD and bombed so hard Activision shut down the freshly purchased Bizarre Creations as a result.
Games like GT5 and Epic mickey may have disappointed in certain regions (reverse regions actually, Mickey in Europe, GT everywhere else) but neither is anywhere close to a real "bomb".







