Probably a bit of a stretch as Mustaine was in the proto lineup, but Megadeth are 10x better than Metallica.
Future of the left.
The Walkmen and Jonathan Fire*Eater.
Silver Mt Zion at their best
Fugazi
Black Country, New Road
Underworld
Wings - the band The Beatles could have been.
Empty Country are at least equal but possibly exceeding Cymbals Eat Guitars (not in popularity admittedly).
The Tubs and Ex- Void are both better than Joanna Gruesome (not a knock on them though).
Fightstar
The Mars Volta > ATDI
Beady Eye
Hot Snakes
I had thought cloud nothings were originally a side project but Google is not backing me up on this fully.
Crowded House. (A handful of songs aside, I always found Split Enz quite irritating.)
Spacemen 3 and Spiritualized
Slint and The For Carnation
Doves and sub sub