Lyrics are hugely important. A song with rubbish lyrics is only a song; a song with lyrics that connect with you is a story, a fable, an insight.
For me, the best music works on both levels, but I'd rather compromise with music than lyrics. Even if that Black Eyed Peas song was written to the best musical accompanient ever, I wouldn't be that bothered about it. There's no emotional connection there. Whereas Joanna Newsom (for example) could write absolutely awful music, but I'd still want to hear about monkeys and bears and beached whales because there's a real connection.
Lyrics > music.