I agree. But in fairness to Bobby (and, holy shit, I think that's the first and only time I'll ever type that sentence)... I don't think anyone can sing the Jerry songs well enough where I'll be okay with it.
Surprisingly (or not), the closest was probably Trey during Fare Thee Well (or Terrapin). Oteil doing China Doll also might fall in that category. Joan Osborne wasn't offensive on some stuff, too, I guess.
Actually, I guess I was also okay with the Brokedown Palace from FTW. It was over the top Bobby, but still worked for me.