After his initial couple of shows on "Taxi," he only got two "rises" out of me: One, to arise to change the channel. The other, the "rise" of the contents of my stomach if I didn't get up in time to change the channel.
After the novelty of him (quickly) wore off, there just wasn't anything.
(I don't believe this website--Just someone cashing in.)
I'm not easily amused, but I often found him hilarious, particularly when he did the Elvis thing.
It's not necessarily "humor" (although Rich Little and Frank Gorshin might argue), but I recall watching some network show back circa 1976 where they introduced "Elvis" as their special guest (I was dumbfounded), and it wasn't until the closeup that I realized it wasn't the genuine article.