Sometimes it's not the cringe factor, but the cheese factor. Several bands I like have songs about their children, and they are nearly always trite and corny. Just because you can write a song about how great it is to be a parent, doesn't mean you should...or that anyone else will care.
Sometimes it's a case of a really odd musical pairing, (Chris Cornell produced by Timbaland, anyone?) other times it's a seemingly random guest vocalist. (Lil Wayne on a Weezer song? What the hell is that all about?)
My beloved Weezer is also guilty of another musical offense: Letting other members of your band sing vocals. Three tracks on 2008's Red Album have everyone singing, even the drummer. We saw how well that worked for the Beatles.
Thankfully, the drummer singing worked out well for Dave Grohl, who became the frontman for Foo Fighters after Nirvana. In turn, their drummer Taylor Hawkins sings lead vocals on one song that is a glowing example of this practice done right: "Cold Day in the Sun."
What is your least favorite track by a band you love, and why?