Their bassist, Pete Wentz, used to be a co-worker of my uncle; Pete used to drive him home from work.
Sadly, that's the only thing I appreciate about them, apart from their lyricism, which is hit or miss for me. Musically speaking, there's not much separating them from the rest of the genre. Speaking of which while claiming to be pop/punk, feels much more like pop, which strikes me as odd.
In sum, while I sometimes enjoy their lyrics, the rest comes across as just another brick in the wall known as modern music.

[Yes, I've listened to all four of their albums; it wouldn't be fair to review them without doing so]