U2:
They were first called Feedback when they formed in 1976, a clear rock-oriented name. In 1978 they became The Hype but a punk friend told them this was a rubbish name for a band (maybe not in those exact words), at which point somebody suggested U2 because it was a spy plane, a submarine and had an air of inclusivity about it (you too). So like many band names, it just sounded good at the time.