Mass Effect 1 - Regarded as one of the best reasons to own a 360 when it launched, but seen as repetitive and near-unplayable by the time the second game came out (albeit the Legendary Edition did a lot to restore its reputation)
Sonic 4 Episode 1 - When it launched, it was seen as the franchise getting back to its roots after Sonic '06 and various other flops in the late 2000s. And then Sonic Generations came along and rendered the whole Sonic 4 project basically irrelevant.
Hitman Absolution - I think people were just grateful to have the franchise back after it looked dead and buried for so long, as opinions really turned against this one at lightning speed after a few months.
Phoenix Wright Ace Attorney: Dual Destinies - See above.
Mega Man 9 - Bit of a borderline case this one, as it's still better-regarded than a lot of other Mega Man games, but more people now seem to see it as a bit too slavishly loyal to the formula of the early games, while Mega Man 10 did a better job of putting a fresh spin on the 8-bit formula.







