I can say that I'm way more likely to like a song with a pleasing tune and blah lyrics than an annoying tune for which I probably won't even care to hear whatever is being said/sung. That said, I refuse to listen to any song that has profanity practically every other word. Of course, complementing words and sounds well is what makes an awesome song, but it is very difficult to pull off--which explains why it remains so rare for me to truly like a particular song based on both its lyrics and its instrumentals. That's also why I find it occasionally nice to just listen to pure instrumental music.
Lyrics most of the time, but i also like some songs just for the beat. It really just depened on which song it is for me. I like the song "What i've done" for example just because of the awesome instrumental intro.