Best for me: Meshuggah, Soundgarden, Gwar (because of their theatricals)
Worst: Cradle of Filth ( love the music but Dani is horrible live)

Job For A Cowboy were the worst band I have ever seen. Utter garbage and I have seen some crap in my time.

Best - Alexisonfire, Streetlight Manifesto, We Were Promised Jetpacks
Worst - IllScarlett

The best live band I have ever seen is Muse. I have seen them performing three times. One time in a small stadium and twice in a park. I liked the second and third time the most because there was fresh air and there is a relaxing festival mood. At the first concert I almost fainted because of the heat. The first gig took place in Brussels, the second gig took place in Nijmegen and the third gig took place at Werchter Boutique.
The first and second concert was during their Resistance tour. I really liked it that they performed exogenesis part 3: redemption. They play really well live and I would recommend everybody to see a performance of them. The voice of Matthew Bellamy is unbelievable. He is a great musician and very talented. I loved it when he played on the piano. The intros of each song were very fascinated and I liked the improvisations. I was very surprised that Chris and Domenic played Nishe. I think only the real fans know that song. The décor was nice but not overwhelming, but I didn’t mind that. I rather listen to good music than look at a spectacular show.
The third concert was at Werchter Boutique. The stage was amazing! They used a catwalk. This concert was more spectacular than the other two concerts. They used the robot of Unsustainable that was very cool. They used actors and acrobats. When they played Blackout I was really amazed. I didn’t expect that they would play such an old song. But it is one of my favourite and every time I hear it I get the chilling. I have to admit that I cried during the performance because it was so beautiful . they also played Unintended, which is also a beautiful song.

Worst was Neil Young without Crazy Horse. It was so bad that I got up and walked out in the middle of it because I couldn't take any more of it.
Best was ZZTop on their Eliminator tour back in '83.

I'm not even a big fan of them but NIN at Woodstock 94' was a pretty bitchin' show
They were really heavy live. Most of the songs I didn't even recognize.

Hope I don't offend anyone but probably the worst was this band called Burnt Offering.
They weren't even that bad, but they opened up for every Chicago show I went to for a while.
Obituary, then Kreator/Coroner, then a Forbidden/Sacred Reich show.
They would never be listed on the bill either.

We'd be anxious to see the local opener and every damn time, "Burnt Offering"...
Then you'd hear a wave of moans and swearing sweep across the crowd...lmao.
The really weren't that bad, I just saw them live way too many times when I didn't want to.

Man, so many good ones. Guided by voices, SRV, gang of four, Replacements. One of the worst was probably Brian Jonestown Massacre.

Paramore at Leeds fest 2012 - aweful.

Best: System of a Down
Worst: Raggabund (srsly. those guys were just awful. That's the problem when bands have only 1 good song.)

Best: Killing Joke, Ann Arbor, the Dirt, Extremities, and Various Repressed Emotions tour. At the Nectarine Ballroom, a concert that brought in some of the mightiest music that trendy place could ever get. Jaz was great, and everyone else were at top form as well!

Bo Diddley - a concert in 1989 at a club in Downtown Detroit. This was in support for Breaking Through the BS and it was a classic gig. Seeing a Legend that will never let you down in a good club in Downtown Detroit...yeah!

UK Subs/Broken Bones - May 13, 1988 at a disused Porn Theater called the Harbor on Jefferson Ave. in a suburb just south of Detroit (which used to be a first run place), seriously giant sized with a balcony and crumbling down - no better way to end my Punk Teens and Early 20's with this kind of show. There was another Punk show soon after but sadly I did not catch that, but this time it was The UK Subs on a stage that has seen a lot of strippers go on and off. Thankfully I stood up all the time - who knows what was on those seats!