Well I'm biased, but Bernie Taupin was always a favourite, at least before he got lazy about 26 years ago. He used to paint some lovely pictures, usually in EJ's lesser known songs.
Neil Finn, Jerry Cantrell, Aimee Mann, Tori Amos (when she's not pretending to be a fairy or a goblin or something), Ben Folds writes some deceptively clever stuff, and Bernard Fanning writes a colurful lyric. Always had a soft spot for James Taylor and Carole King as well.
Could never pick an absolute favourite though.
Oh wait, of course. PHIL COLLINS!!!! What a genius!!!!!
PS. NOT!!!!!!!