Oh, difficult question....I'd say, as already stated before, it depends on the genre. Someone mentionned dance for example....I could imagine that the beat is the most important factor there, same goes with some pop productions where it's more about a stunning melody or an overall feeling the song wants to deliver...Completely different in the singer/songwriter genre for example where the singer tells a story, maybe only backed up with a piano or acoustic guitar (thinking of Bob Dylan or Joan Baez right now...)
I must admit, I am a lyrics freak, and it already happened that I disliked a song with great melody and music just because I couldn't connect to the lyrics. For me, music gives me the chance to express what I couldn't put in spoken words but what comes out easily in a delicate melody and a poetical lyric....
Due to the fact that I am a dj/ b-boy, I listen to the beats but if the lyrics are not up to par, I tend to not really enjoy the beats. You cannot have sick lyrics without a hype beat in my opinion either. Hip Hop was started with the dj's and B-boys. Dj kool herc first started mixing the drum break solo's of funk records back in no later that 1973. He started dj'ing block parties bck in 1968. He noticed the dancers would only do thier gymnastic / acrobtic moves on the drum solo of the records so he started mixing his records so that he could extend those 15 second drum solo's into 2 minutes long, indefinitely, until the needle breaks or until the dancers would want a new song put on. He came up with the term B-boy because the dancers would only dance at the breaks part of the songs. He later had local mc's say party rhymes over his dj mixes. Grandmaster Flash perfected his innovative yet rather choppy style of dj'ing. Flash was the first turntablist. Africa Bambataa (a former Black Spades gang member) started out as a dj. He organized the first of many Hip Hop battles at the Bronx River Community Center back in the 70's. So I feel that the beat is what helps to makes Pop, Funk, Hip Hop, House, rock and roll, etc. listenable or not listenable. I feel as far as hip hop is concerned, I would rather watch some ugly fat mc or dj who are Jedi's at what they do rather than an over produced top 40 star who clearly cannot do at a concert what he or she does in a studio. That is my say. God Bless.
While I love a great beat, In my opinion if the lyrics ain't saying ....then it ain't worth ....But, there must be a perfect blend of a great beat and great lyrics. Lets face it, must young and some older folks only pay attention to the beat in club music; however, it is up to us to change that. I do poems and spoken word which is about lyrics. And, even with poems and spoken word people want to hear some kind of beat in the background sometimes. Personally though, if the lyrics is not say something positive, or at least interesting I tune it out. Back in the 70s and 80s people use to listen to the lyrics, darn, I think I just told my age. :) What we have to do is to know our market, and remember our market sometimes change.