8. Guitar Hero
When the Guitar Hero franchise exploded in 2005, it seemed like the franchise that absolutely could not be toppled; with its increasing array of instruments and shrewdly-selected collection of popular songs, few of us expected that the bubble would burst quite so fast. By 2010, the series was well on the decline, and last year, it was put on an indefinite hiatus, owing to disappointing sales of the last game. The problem became over-saturation; by the late 2000s, Activision had settled into a comfortable niche of releasing a new numbered game every October, with a bunch of new songs, for a £40 price tag. The problem is that while the songs remained great fun, the formulaic repetition for the same cost didn't feel like value, and some crassly-priced DLC hardly helped either. It's a difficult conundrum because how do you shake things up for a game that is so simple and not at all reliant on story? The solution would probably have been to divert to a DLC-only approach, whereby a number of songs were released each week - at a reasonable price, mind - but greed, as it usually does, corrupted an initially brilliant franchise and made it quite banal.