1. Don't Stop Believin'
The Glee cast's very first full-group number is still its most popular. No surprise, considering Journey's "Don't Stop Believin'" is a long beloved and often-downloaded tune outside of "Glee." But Rachel, Finn and co. still manage to deliver a fresh take on this anthemic '80s song about the power of sheer optimism. When the "Glee" kids sing, "Everybody wants a thrill," you get the feeling they may actually mean it more than anyone who's sung it before them -- and that's saying something.