Both.
I hate it when amazing talent is wasted on crappy lyrics.
prime example: Bruno Mars
I also equally hate it when amazing lyrics are wasted on crappy singers.
I think you should have both in order to be considered a real artist.
prime example: Lady Gaga, Pink, Evanescence etc.
And i also don't like when great lyrics are wasted on screamo either.
I like some screamo ...but i can't take it when an entire song is screaming. There needs to be a balance between singing and screaming. Otherwise, i can't make out what the crap you're saying. And when there's something really substantial being said...it's totally wasted on what sounds like 3 and a half minutes of bad regurgitation. Just putting that out there as well. XD
Vocals!!! If the person sounds like a dying cat with the most amazing lyrics on earth, i wont be able to listen to their awful voice no matter how good the lyrics.
Damn it, voted for lyrics, but i wanted vocals. Vocals are key for me, just hearing a sweet voice singing a lullaby, like Adele's First Love, i fell in love with that song instantly It's so soft and cute, I wish I can sing like that. I wish my family had talent genes
But Lyrics I suppose I mean I have to like the song itself. A good song is a good song no matter who sings it. Vocals can make a song better but its not the end all.
I would go with vocals. Based on vocals i decide if a certain artist/group will be part of my music collection or not. I do read lyrics from time to time, but it's not a decisive factor for me in terms of liking an artist or not
Vocals are more important. Production and lyrics don't mean that much to me, within reason. Everything comes together like a puzzle in the end though. So it's really hard for me to pick just one.
Damn it, voted for lyrics, but i wanted vocals. Vocals are key for me, just hearing a sweet voice singing a lullaby, like Adele's First Love, i fell in love with that song instantly It's so soft and cute, I wish I can sing like that. I wish my family had talent genes
Lyrics.
Like i've said before. You can have amazing vocals but crappy lyrics ruin it for me (example: BRUNO MARS)
But a not so perfect voice and amazing lyrics can win me over (Example: Avenged Sevenfold)
It's so soft and cute, I wish I can sing like that. I wish my family had talent genes 
Thats my fav Adele song