also, ignition (remix) is not representative of R. Kelly's R&B suavity. I'd go with Step in the Name of Love, Happy People, I Wish, I Believe I Can Fly, I'm A Flirt, or Hotel. Each duo of songs I've presented, show varying degrees of the R&B scale, all of which Kels can do well. The first two identify with wholesome african american family life, and the unconditional love that is held there. The second two show his ability to really portray emotional strength in the face of the "bad" life typical of the poor african-american community. And the last 2 show his "let's get down to fuggzin"/club hit ability.
The dude did a collabo album with Jay-Z, arguably the greatest contemporary rapper, and then feuded with him while on tour, reportedly leading to some of his crew killing a member of Hova's (not sure if it was killed or maimed, but killed sounds better). Hov didn't even do anything about it, because Kels is that legit and cool and smooth and playboy.
Once "Trapped in the Closet: The Next Installment" comes out, he will have over 40 "tracks" that form a "hip-hopera", something no other artist has done, and while the quality of the music and lyrics may not be his best, the fact that he's able to even continue a rhyming storyline that, while quirky and outlandish, continues to flourish. He described it as an "alien" because of how it has been able to continue growing, seemingly on its own volition, as Kelly has in the meantime written and made a bunch of other tracks (and even an album if I'm not mistaken).
So yeah, he's a bit of a joke at times, and being the King of R&B probably isn't as awesome of a title as King of Rock and Roll, but I really do think that at the end of the day, people will look back at R. Kelly's career with fondness.