Not necessarily the best song, but just your personal favorite song. I have a few in contention. I love Radiohead's "Let Down" and Pearl Jam's "Black" but the one song I always come back to and think damn that's a great song is the Pumpkin's Mayonaise. I mean the opening chords written by Iha were amazing, the lyrics were surprisingly perfect, the solo was spot on, the production was perfect and the overall the feel of the song is amazing. It's just an incredible song.