As for the Eagles, I demur. I'm not a huge fan of theirs, but Bernie Leadon was an authentic bluegrass voice on the band's early records -- and quite good records they were too.
Yeah, sure, they had that awful backbeat on everything, but so did Newgrass Revival, a unit with better licks but less integrity -- in my own humble estimation.
As for "most excessive," who can forget (a record club sent me their CD by mistake a number of years ago) the inimitable and thankfully forgotten Whitesnake.
Def Leopard is a very close second. Unless, of course, you count "Let It Be."