Marillion

While the U.K.'s Marillion aren't the best-known rock band in the 21st century, they've influenced many acts that followed in their wake, directly or indirectly, from Porcupine Tree and Radiohead to the Pineapple Thief and Gazpacho.

They are rightfully credited with having established the neo-prog subgenre, and have explored many types of music over the decades that, thanks to their expert musicianship, have celebrated their long, inventive passages for electric guitars and keyboards.