With a good beat that sounds like a slow clap, and a fantastically singable melody, So Sick is one of those songs that will appeal to anyone and offend no-one. Even the lyrics are generic so that everyone is able to relate to them.
Ne Yo sings of how he is "So sick of love songs, so tired of tears", telling us how he relates all the love songs on the radio to past failed relationships. This has to be an emotion that everyone has felt at some point, and is evoked nicely in the up-and-down lyrical melody and slow clapping beat.
Though not outstanding, the song is comfortable. You feel upon hearing it as if it were a song that you knew all along, and are simply hearing again. Perhaps that was Ne Yo's intention - It is definitely how to write a hit song with mass appeal.
It would be nice if there was something to make this song brilliant, but as it is it is just a very enjoyable song, good for crooning along with - especially if you've had a recent break up.