5.) The Wonders
Ah, That Thing You Do. It was filmed in the grand nostalgic tradition of the '90s, coming out as Britpop bands languished in '60s moddish fashions, the '70s was old enough to be thought on fondly, and nobody knew what sort of catastrophe the new millennium would bring. That Thing You Do embraced the early '60s dream of new rock and roll, creating The Wonders as one of the (badum tsh) forgotten one-hit-wonders of the early Beatles era. The songs will likely worm their way into your head long after the movie is over.
4.) The Pussycats
No, not the cartoon. I'm going with the absurd, live-action film remake of Josie and the Pussycats. The movie retains very little pretense of a fourth wall, allowing a ridiculously self-aware plot to plow though early millennium commercialism and self-satire. The band itself shines with the sort of bubblegum, girl-power pop punk that people tend to list as a "guilty pleasure" as they belt the lyrics in the shower.
3.) The Commitments
Not content to be a mere movie, The Commitments is also a stage show still playing. The rough-and-tumble Dubliners make you want them to succeed all while sucking you in with some excellent funk. Even if it doesn't work out in the end, the music has impressive staying power as more than just an earworm.
2.) Spinal Tap
Not content to be a mere movie, the titular band from This Is Spinal Tap became a real band! With tours and reunion tours popping up through the year, it's difficult to not accept the silly power metal band as an actual musical force.
1.) Blues Brothers
Formed from two ace comedians and on a mission from God, the Blues Brothers were only barely contained by their self-titled movie in the '80s. Dan Akroyd and John Belushi made the band official; their "backup" in the film consisted of real musicians and not actors. Hitting up standards and writing their own music, the band continued to put out material even through the loss of Bushemi later on.
The Soggy-Bottom Boys - That outlaw one-hit-wonder from Oh Brother, Where Art Thou?
The School of Rock - The band made up of classically-trained kids and Jack Black
The Lone Rangers - The hot-sauce-gun-wielding band from Airheads