I don't know if you could say that a lot of people think it sucks, since it got good reviews back in its time, but I'm gonna say the Serious Sam games.
It's just that people go into shooters these days hoping for a massive single player campaign with a gripping story, deep characters, varied mechanics, and blah blah blah. This game has none of the above. It's a big, dumb action game where you fight dozens of over-the-top enemies with over-the-top weapons in crazy locations, with only one goal in mind: be as fun as possible. And dammit, that makes it one of the best games I've bought in a while, because the focus isn't being as technologically impressive as it can be, it's to be fun.