There's way too many different things that make a song good, too many to articulate. Such as musical talent, love for the band, lyrics, meaning, uniqueness, emotion... etc etc.

qftw.

If it had to be just one single thing I would have to say emotion. Nothing bugs me more than emotionless instrumentals or over-produced radio garbage. When a band puts out a song to show off technical skill it just makes me want to cut myself. I'll take Gilmour over Satriani any day.

If it's not written by Radiohead.

Why so much hate?

Good melody/arrangement/vocals/direction of song.

as long as it contains lyrics about breakups with boyfriends, lust, deception, or just a simple love song shouting out how much you love your partner and how you couldn't live without them <3

Well it definitely has to make me want to dance<3. And if I can relate to it somehow on an emotional level, like if it's a break-up song or something about global warming.

high five babe! *holds palm out and tilts head*

I predict that the two posters above me are 9th grade girls obsessed with Dashboard Confessional and such.