Pick your musicians any genre you like. For me; Jimmy Page on guitar, Niel Peart on drums, Geddy Lee on bass and backing or lead vocals "depending on song", and Robert Plant on lead vocals. Alternates would be Tommy Iommi for guitar, John Bonham or  Bill Ward for drums, Cliff Burton for bass, and Ozzy Osbourne for vocals. As you can see my perfect band is mostly a Led Zeppelin, Rush hybrid.

Paul McCartney playing everything

Vocals:  Maynard James Keenan

Guitar1:  Kirk Hammett

Guitar2:  Mike McCready

Bass:  Les Claypool 

Drums:  Bill Ward

In a perfect scenario, Neil gets hit by a bus, and it's me, Al, and Ged.

Shagrath. Of Dimmu Borgir.

He plays guitar, bass, drums, keyboards, sings, and does mixing and editing.

John, Paul, George and Ringo.