Thought the ending was dumb and made even MGS4's look good in comparison
MGS4 has more problems that just the ending though. It has so much fanservice for instance that it got in the way to tell a decent story, but in reality after Metal Gear Solid on the PSone there wasn't any story left to tell... MGS2 more than a sequel it was a game about media manipulation among other topics and MGS3 was kinda like a celebration of the early days of the franchise.
MGS4 is just a thing that should have never happened really, because is a product that was created in the end for the fans and fans hated the shit of it (and they still do).
Sorry for going off-topic by way.