The Amazing Johnathan has been a staple of the Vegas comedian/magician scene for many years. I first saw his act on September 12, 2001 as he was one of the few performers still putting on a show following the attacks.
Unfortunately, the same act he had then is the act he has now at the Sahara Hotel. This is the only reason I don't give his act a 5 Star Rating.
He is a very loud and fairly offensive comedian akin to Sam Kinison or Bobby Slayton, but not quite as rude. His assistant, Psychic Tanya is very entertaining in a bubble-head blonde kind of way and works well with Johnathan's annoyed persona.
Pretty much none of Johnathan's magic works, but that makes it funnier. His comedy is a mixture of visual gags and just plain picking on people. He's an acquired taste that may not work for everyone and I would recommend checking him out online through Youtube before attending the show.
I found his tickets on sale through one of the local 1/2 price ticket outlets. Each ticket ended up around $33 which was very reasonable.
Update (03/17/08): We received comp tickets to last nights show which is now located in the Harmon Theater at the Krave Nightclub. The seating here is much better than at Sahara; there is no bad seat in the house. The act is the same (of course, we only saw him 3 months ago) with a few changes.
This particular night he was entertaining Criss Angel in the audience so he removed a particular scene with a live rabbit to show the audience what Criss Angel's "Mindfreak" show would be like in 50 years. It wasn't THAT funny to most of the crowd, but Criss couldn't stop laughing. I would guess that is all Jonathan was aiming for.
All in all the show was still good, I was still laughing and enjoying everything even knowing what was going to happen next. Johnathan was in a much better mood this time around, so that added to the enjoyment. Frustration from working at the Sahara before must've been getting to him.