Need I describe the purpose of the thread? Haha.
Anyways, my favorite serious lyricist is Peter Sinfield of King Crimson. I love his use of poetic imagery that weaves itself into cryptic poetry. It can range from beautiful to sorrowful to playful and it does so quite amazingly.
For satyrical lyrics, definitely Zappa. He's always so blunt and hilarious. His religious, political and social satire is spot on, the use of language is always comedic. He also has his share of random bizarre songs that are humorous in their nonsensical nature.