NME has compiled a list of the top 500 songs. The list was based on submissions from their writers, both past and present, of the top 50 albums of all time. They combined those lists with their own "best tracks of the year" lists. Over the next few days, their website is sharing the entire top 500. Here's 500 through 401.
Nirvana released Smells Like Teen Spirit on September 10, 1991. That was two weeks before their second album, Nevermind, came out.