> The lead singer caught my eye and gave me a wide grin

Daft Punk doesn't have a singer and unless it was a very early show they wouldn't have seen them smile. Most big beat shows wouldn't have a dedicated vocalist. I'd guess Underworld or Prodigy, but lean toward Underworld.

Daft Punk didn't have helmets in the 90s, did they?

Correct, seems like my memory failed me on that one.

Ah, missed that bit entirely, was going mostly on the story of being front and centre and being smiled at - it's an apocryphal story for TGD.

Now I"m thinking, the mention of digital formats doesn't make much sense either ^_^;

Thats what came to mind. Daft Punk, the Alive 2007 recording

Alive 2007 is a bit late to be the 90s though

Underworld, 1998, live at The Mayan.