I'd argue Cee-Lo Green. Cee Lo Green Is... The Soul Machine dropped in '04. It featured Cee Lo rapping, singing, doing poetry, and producing. In '06, Gnarls Barkley dropped St. Elsewhere and that was Cee Lo mostly singing. Same goes for Gnarls Barkley's Odd Couple. Then in 2010, Cee-Lo released the Stray Bullets mixtape, which again featured him mostly singing as was Lady Killer, which came out the same year. The only real blemish on his catalog is the Goodie Mob album that dropped last year.
Now, Cee Lo hasn't been as big commercially, but he artistically, it's hard not to recognize the work that Cee Lo has put in. He's better than Kanye in every category except maybe producing. Lyrically, Cee Lo goes in even when he's singing.
