Hmm....
Firstly, I'd need a field and a select bunch of festivalgoers.

My lineup would be

Blondie circa 1981
The Happy Mondays
The Prodigy
Pop Will Eat Itself
Faithless
Orbital
Ian Dury and the Blockheads
New Order
(Bicycle Repairman "you're also a bit of a wanker", Wed 30 Jun 2010, 10:57, 2 replies, latest was 16 years ago)

Would it be an earthy field?

( Naked Ape call me Caitlyn, Wed 30 Jun 2010, 10:59, Reply)

The Happy Mondays played a festival near me a few years back
they were rubbish.
( Peej, Wed 30 Jun 2010, 11:05, Reply)

Were they off their faces?
A colleague saw them at Glasto in '95 and said they were pretty good.

Maybe they played better mullered?
(Bicycle Repairman "you're also a bit of a wanker", Wed 30 Jun 2010, 11:06, Reply)

Actually, I heard New Order's live version of "Love Will Tear Us Apart"
And it was dire.
(Bicycle Repairman "you're also a bit of a wanker", Wed 30 Jun 2010, 11:07, Reply)

In the 90's I bet they were awesome
but I saw them in 2006.
( Peej, Wed 30 Jun 2010, 11:10, Reply)

Should we put some sort of optimal date next to our choices?
I put Blondie circa 1981 mainly for aesthetic reasons but also to ensure "Maria" is off the playlist on temporal grounds.
(Bicycle Repairman "you're also a bit of a wanker", Wed 30 Jun 2010, 11:12, Reply)