The most recent supergroup nominee

What’s the most recent group that got people thinking they could really become a supergroup?

Guns ‘n’ Roses: Truly great stuff, imploded

Nirvana: Ditto

Pearl Jam: Some big albums, then faded from view

Metallica: Burst from the underground to massive popularity, then flushed it away with only three albums in the next 16 years, and none of them were actually good, and one was awful.

Oasis: Took Britain by storm, I haven’t heard of them in years

So, did I miss any in that time period, and are there ones since then?

You are using the term “supergroup” in a way that most people don’t.

You’re using “Supergroup” in a different manner than the term is normally used - it normally means a band made up of people famous for being in other bands.

But sticking to your usage, you clearly missed the Smashing Pumpkins - an enormous critical (even the snobbiest critics had to give it to them) and commercial success (most of the albums went multi-platinum) who made the most legitimate mainstream double album since The Wall.

Teen Titans?

**My Morning Jacket ** is being touted as one of the best live acts in existance today. They’re nowhere near “super group” status, as you define it, but watch out for them.

In the traditional sense of Supergroup in being a group made up of people from other groups - Velvet Revolver, Audioslave, and The Raconteurs all fall into this category. Though I believe Audioslave has broken up recently once Rage Against the Machine reformed.

Dashboard Confessional, expanded to include former members of The Promise Ring and Sunny Day Real Estate

Maritime, composed of former members of The Promise Ring and Dismemberment Plan.

'Kast
Wu Tang

Though it’s been more about individuals over the past 10-15 years, of course. Biggie, Jay-Z, Pac, Nas, Eminem, T.I., Kanye, Snoop.

I think the way the OP puts it, the best example of a mega-popular group right now is Coldplay. A few of the bands with “The” in their name (like The White Stripes or The Killers) might qualify too.

A few more:

NSync were huge for quite a while, and then spawned an even bigger solo artist
The Dixie Chicks