Iron Maiden, Somewhere in Time tour.
Runner up has to be the Prince cover band I watched at a bar.

There are a lot of contenders but I think I have to go with Foo Fighters at Milton Keynes last July, they had the drummer from Queen on stage for 1 song and then later Alice Cooper and played a few of his songs. Absolutely phenomenal night, also greatly helped by the support acts (Tame Impala, Death Cab for Cutie and Biffy Clyro) all being on top form.

Black Sabbath(original line-up),Ozzfest 2001 Milton Keynes,England

I'd been a fan of Sabbath for years so finally getting a chance to see Ozzy,Tony,Geezer and Bill play together was just epic

A close second would be Judas Priest,Megadeth and Testament in Dublin in 2009.Three of my favourite bands on the same stage in the same night

I've seen High on Fire, Mastodon, and Dream Theater, among others, but those rank in my top.

Best concert will have to go to Our Lady Peace at Houston's House Of Blues in 2010.

<3 OLP
Simply awesome music, plus the fact that we get to live in the VIP lounge whenever we want because my friends and I have connections. :P

Concerts really arent my thing. But the best one I have seen was the Death Fest which takes place right down the road from me in Hünxe once a year. Technically, its a festival, not a concert, but you get the idea.

Why was it the best? Well, some dude in the crowd threw up all over a female friend of mine on the first day. I swear, I couldnt go the next 2 days because I was still laughing.

Al and the Black Cats - Aachen, Germany. They played before some punk band I did not give a shit about and before the asian punkband Cobra. During Cobra played I found myself with two members of Al and the Black Cats dancing in the front like batshit crazy, after them I continued dancing during the performance of the band I came there to watch!

AC/DC. I'm danish so i watched it in our park. It was a little bit like watching American psycho. disturbing, yeah, of course. The guitarist bassically shows his underpants. in the middle of the concert, but that only lasted to seconds, and was followed by a 20 MINUTE, GUITAR SOLO.

Can't really say more than that.

by far and away AC/DC. They may be getting a bit on in years but they still know how to have a really good time playing their music, which means that it is impossible not to enjoy their show. Also cannons. Green Day comes in a little bit behind--wasn't expecting them to be as good live as they actually are.

Tie between Def Leppard and A Day to Remember.
Def because they can still nail their classics,
and adtr because of the band itself and because I got to see some scene girl get a broken nose. Classic.

I've been to very few live concerts over the years. There's one group I see almost every summer, but they're not really a big name. Great show, though. Not sure if I'll ever experience the spectacle of a super-famous rock act, so I take what I can get. (and enjoy)

I've been to more electronic music events more than anything, but of the newer acts I've seen (not just DJs), Pretty Lights' laser light show is insane enough now to make Pink Floyd blush. If his shows can count as a "concert" on some level, then his NYE show this past New Year had one of the most impressive lighting rigs I've ever seen in action.

Well I've been to

Iron Maiden 2005
Kiss 2008
Iron Maiden 2008
W.A.S.P. 2009
Stratovarius 2011

and the Maidens and Kiss was of course bigger concerts while wasp and strato were at smaller places. It's hard, because I had seats in the Maiden and Kiss concerts while in wasp and strato I was first row almost touching the guitars of the band members.
I'm gonna go Maiden 2008 I think, althou they were all awesome. A shame I haven't been to any festivals yet, really trying to get tickets this summer.

The National in Chicago in 2010- every song builds into a crashing crescendo of perfection

K.M.F.D.M.

Firewater, '09 or '10.
Though the Dropkick Murphys gig last week came close to knocking it off the top.

I have seen Blondie, the Pretenders, Little Red, You am I and Cold Chisel.

Chisel and Blondie were absolutely fantastic.

Most TECHNICALLY proficient concert I've been to was Opeth. They played to damn near perfection.

Best concert I'll GO to will be Taylor Swift. March 13th. Can't wait.

Tough one...

The Dream Theater/Iron Maiden show was phenomenal, but with how big the stadium was, it was a tad impersonal.

The multiple After Midnight Project shows I've been to have all been a blast, especially since I've been on stage for one of them, and I'm cool with the band.

The Edguy/Kamelot show was a lot of fun, especially talking to Tobias Sammat of Edguy afterwards (he kept trying to give me and my friend alcohol. Cool dude).

The Sonata Arctica/Nightwish show was absolutely phenomenal. Two of my favorite bands ever together, and they destroyed it. Unfortunately, it was after Tarja left, and while I like Anette, I don't like her as much (she did kiss me on my cheek though. That was nice).

The Warped Tours I've been to have been a lot of fun, but I don't know if those count (that is where I saw Closure in Moscow, Enter Shikari, and The Rocket Summer though...). Yeah, I've giving it to the 2010 Warped Tour.

They're all great in their own rights though. But it won't matter after the 24th, because I'll be seeing Emilie Autumn, VIP ticket. I'm fully expecting it to be the best day of my life.

EDIT: Or the Bright Eyes/Mountain Goats concert I went to. I've never seen someone be more happy to be making music than John Darnielle.

Turisas were damn near brilliant live, especially when they played Rasputin.

David Savage:
by far and away AC/DC. They may be getting a bit on in years but they still know how to have a really good time playing their music, which means that it is impossible not to enjoy their show. Also cannons.

I also agree with this. AC/DC awesome live.

I'm into a lot more lesser known bands than the ones listed so far, not because I'm a hipster or anything, it's just the type of music I like, plus it is easier to see newer, fresher acts in concerts or at shows and it is generally a lot cheaper. It would be really hard to pick a favorite though, there are a lot of shows that have special meaning to me for one reason or another. The best show I ever went to was probably a local show, it isn't worth listing the bands because there is no way in hell anybody would recognize them, lol. It was less about the music and more about the people I was there with.

it's a tie between tool and judas priest. tool had amazing visual effects whereas judas priest just plain rocked.

By far the best band i've seen live is Tenacious D, second place was linkin park & jay-z

Top 3 (not neccesarily in order)
Mumford and Sons, Frank Turner, The Decemberists

Its a toss up between

The machine head DVD they shot at Brixton (Elegies)

or

Turisas and their 2008 tour...Which had Alestorm as the opener...which fucking ruled.

I've been to Iron Maiden, Judas Priest, and Mayhem Fest last year. I saw a lot of good mother fucking bands.

I'd say Judas Priest wins though because on the same bill was Thin Lizzy (who still kicked ass without Phil Lynott), Black Label Society (Zakk Wylde did an 11 minute guitar solo) and Then Judas Priest blew my mind away with Halford's singing, the amount of lasers, solos from Glen Tipton and Scott Travis, and great setlist of some never performed before that tour songs.

After that show I can die happily.

Close second would be the Iron Maiden concert because of the showman ship of Bruce Dickinson and the incredible backdrops and stagecraft and Eddie's new look.

Best gig eh? Cant really decide between Rammstein live in Athens or the Sonisphere with Mastodon, Slipknot and Iron Maiden in a row...

I can't say for sure the best show. but i know for sure the best opening of a show i've seen.

Young guns, the rescue rooms nottingham. The air was sweaty, the room was bouncing, the atmosphere was electric. Gustav jumped into the crowd, there were crowdsurfers, and the 14 year olds in the pit were light enough to bounce off anyone who cba with it. And I got into rock city for free with the ticket for a club night, extra winnage!

AC/DC, Black Ice tour. Absolutely awesome, spectacle and performance. But I will admit I am an AC/DC fanboy so my answer was unlikely to be anything different. Still, they are absolutely incredible to watch.

I saw the band Cake when they hit Denver last year. Brilliant performers. I still hope to see U2 sometime though.