Who have you seen perform at concerts/shows?

"You attended 292 concerts of 113 different artists."
According to setlist.fm, which I use to track which shows I've been to. It doesn't include bands for which I've only seen a few songs at a festival.

A small selection of bands/artists that I've seen live:

Beartooth
Billy Talent
Bloc Party
Bury Tomorrow
Dropkick Murphy's
Eminem
Enter Shikari
Five Finger Death Punch
Good Charlotte
Gorillaz
In Flames
Jimmy Eat World
Joji
Millencolin
Nine Inch Nails
NOFX
The Offspring
Pendulum
Pennywise
Placebo
Rise Against
Robbie Williams
Silverstein
Sum 41
System of a Down
Taking Back Sunday
Thrice
Zebrahead

Bands most of you will know:
Depeche Mode (7 times)
ZZ Top (2 times)
Jethro Tull (3 times if you count the Rock Opera theatrical)
Front 242 (3 times)
De/Vision
Sigue Sigue Sputnik (2 times)
808 State
Nitzer Ebb (2 times)
Icona Pop
E-Type
Burger/Voigt
Skinny Puppy
a'Grumh
Thermostatic
Robbie Williams
Pandora
Muse
Sisters Of Mercy
Nine Inch Nails
21 Pilots (2 times)
Combichrist
Cement
Aesthetic Perfection
Ace Of Base
Rage Against The Machine
Clawfinger
Alice in Videoland
Eiffel 65
Engel
Röyksopp
Björk
Santigold
Had tickets to see Rammstein 3 times, but missed all occasions due work (seaman). One of my great disappointments.
Had tickets to see The Prodigy, missed it for the same reason. Damn.

Bands only few of you will know (Swedish):
Rolf Wikström
Lena Philipsson
Thåström
Stefan Andersson
Kent
Leila K/Rob'n'Raz
Totta Näslund (actually a good friend of my parents back in the day, neighbours for a while even)
Orup (3 times)
Lillasyster

There's more though, went to a lot of festivals and shit in my younger days, bands I don't even know the name of, etc...
Back in the day there was also quite a few live performances in small clubs in my hometown, there's bound to be few I've missed to list here.
Add quite a few DJ sets too.

Damn. I saw hundreds of bands perform.
From The Vengaboys to Immortal, bust mostly metal/rock/hardcore. Too many to list.

I generally don't care much about this, the only concert I went to that meant something to me is because I went with my best friend and it was in another city and more of a mini vacation that I really enjoyed and look back with nostalgia, specially now that he's dead and I miss him.
To me music is music, the medium is secondary.

Tha Playah
The Chemical Brothers
Bullet for my valentine
Godsmack
Five Finger Death Punch
Combichrist
Like a storm
Megadeth
Hollywood undead
Papa Roach
Ice Nine Kills
Myrath
Eleine
Evergrey
Bloodred hourglass
Crossing Eternity
Genus Ordinis Dei
Suffocation
Belphegor
Hate
Shadowmass
Carnosus
Obscura
God Dethroned
Thulcandra

No one. I have never been to a Live concert.

no one

Ben Harper & The Innocent Criminals

Alan Parsons Project (could reach front stage easily and almost touch him, you could really feel the bass from the speakers).
BB King
David Bowie (with bootleg shot behind my back).
Eric Clapton 2x
The Rolling Stones (in Arena, awful sound)

Anathema (many times)
The Legendary Pink Dots

most notably: hardwell

Mother Mother is the only band I've specifically gone to see on my own. Said the Whale opened for them, and I was pleasantly surprised by how much I loved the album they were releasing that night, too. Shout out to Level Best, which the singer introduced as the song he wrote for his son with this anecdote:

"Last time I was in this theatre, it was to see a live Peppa Pig show. ...With my two year-old, I'm not some weird connoisseur. I do a lot of Facetime. Today he bought his first thing on Amazon? So uh, that's fucked."

Heroes del Silencio
Pride & Glory (Zakk Wylde)
Aerosmith
Bon Jovi
Mastodon
Kiuas
3 Doors Down
Avenged Sevenfold
Disturbed
Helloween (3 times)
Sonata Arctica (2 times)
In Flames
Turisas (3 times)
Saxon
Machine Head
Lamb of God
Metallica
Linkin Park
Dragonforce

These ones I remember off the top of my head, have seen many others as well.

In no particular order and I'm pretty sure I forgot something like 30% (and also ignoring small local bands):

Robert Plant (First concert)
Whitesnake x2
Deep Purple
Nazareth
Sweet
Slade
Jethro Tull
Heathen and Hell (Black Sabbath with Dio)
Dio
Queensryche
Alice Cooper
Brian Eno
King Crimson
TU (Trey Gunn and Pat Mastelotto) x2
Tony Levin
Adrian Belew
Guns and Roses
Extreme
Scorpions
ELO
Carl Palmer (ELP), Andrea Braido and T. M. Stevens
Keith Emerson
Chuck Berry
Bill Bruford
Sparks
Aerosmith
Dire Straits
Chris Isaac
Glenn Hughes
Greg Howe
Phil Collins
Judas Priest
Nick Cave
Porcupine Tree
White Stripes
Iggy Pop
Tom Waits
Mike Terrana
Slash
New Order
Billy Cobham x2
Avishai Cohen
John Scofield
Colin Stetson
Al Di Meola
Chick Corea & Gary Burton
Aigui
Marimba Plus
Bobby McFerrin
Eric Truffaz
George Benson
George Clinton and Funkadelic
Jean Luc-Ponty
John McLaughlin
Maceo Parker
Keith Jarrett
Jacob Collier (one of the best)
Lenny White
Scissor Sisters
Jose Gonzalez
PJ Harvey
Alt-J
Hot Chip
Andy McKee
Nikki Sudden
Clutch
Electric Six
Bombay Bicycle Club
Elbow
Fun Lovin' Criminals
Brazzaville
Mooncake
Wu-Tang
BartolomeyBittman
IAMX
Huun Huur Tu
Fred Frith
Vacuum (last concert for me....pretty shitty though)

Metallica
Megadeth
Rammstein
Iron Maiden
Slayer
Anthrax
Accept
Manowar
Apocalyptica
Volbeat
In Flames
Evanescence
Guns n Roses
Haggard
and lots of local or not so well known bands

Nine Inch Nails
Slipknot
Seether
Placebo

I am not a fan of concerts, but I did happen to attend a very unusual one put on by Taj Mahal. (The atmosphere was more like a "school dance" than a concert.)

I've seen hundreds of shows (some good, some not so much), thanks to my job, but I've always had a fondness for concerts, and have been attending since I was 12.

Some of the more notable ones:

KISS (numerous times) I'm 6-4 and in his boots, Gene Simmons is an imposing guy
Pantera
Staind
Seether
Disturbed
Pearl Jam
Smashing Pumpkins
Red Hot Chili Peppers
Soundgarden
Slayer
Slipknot
Vimic (Joey Jordison's new band - the singer fell into the orchestra pit)
Suicide Silence
In This Moment (Maria Brink is one of the most memorable people I've ever met)
Lizzy Hale
Joe Satriani
Ozzy Osbourne
Ministry (I actually had someone mistake me for Al Jourgensen back then)
Nine Inch Nails
Marilyn Manson
Rob Zombie (he's so freaking tiny!)
John 5
Van Halen
Zack Wylde
Barry Manilow (one of the most generous and gracious performers I've ever met)
Kansas (got to sit in on their pre-show practice - they do the entire set acoustic before going on stage)
and I'm going to throw Vanilla Ice in here, just because he's a super nice guy and very down to earth

Those are just quickly off the top of my head.

Just to name a few:

Tribal Tech
Chucho Valdes
Herbie Hancock
Fats Fernandez
John Scofield Trio
Eric Clapton
Pat Metheny
Roger Waters

stevie wonder :(((

Elton John, Madonna, Michael Jackson, U2, Sting, Phil Collins, Bee Gees, Electric Light Orchestra.
I think that's it.

Iron Maiden