Both are great but you just can't resist Geezer's lyrical atomic bombs!
The world is a lonely place - you're on your own.
Guess I will go home - sit down and moan.
Crying and thinking is all that I do.
Memories I have remind me of you,
Of you, of you...
I always thought Geezer to be the definitive Sabbath lyricist.
I think Dio and Geezer are great lyricist. It's Iommi's musical writing that makes Dio and Geezer really shine. Probably the biggest reason I could never get into Ozzy, the lyrics. Too add, also, Bernie Taupin is one the top ten lyricist of the past forty years.
When it comes to lyrics, i like both Dio and Geezer but i will give a slight lead to Geezer. The first 3 Sabbarth albums contained Geezers best lyrics imo.