Speak Now is clearly her best album. With showing off her vocals in tracks like "Dear John" to showing the growth in her songwriting with the metaphorical experimentation in the title track, Taylor has clearly shown growth from Fearless. As an addition, I prefer the Speak Now album cover over the others. The songs have more of a variety and she isn't holding back, being unafraid to call someone(Camilla Bell) a **** in "Better Than Revenge" and clearly calling out John Mayer in "Dear John." Although, I do wish she would choose more pop-radio-friendly tracks for better promo and chart success.
