Saw the Clash four or five times between 77 and 80. I was not particularly impressed on any occasion. The first album and London Calling were very good, otherwise... meh. Totally overrated by the London-centric music media. Joe Strummer was the typical angry posh boy.
The Who...? Phenomenal is the best word I can think of to describe them. Light years ahead of the Clash, both live, and in the studio.
Absolutely no contest in my opinion.