The Beatles are certainly not overrated in my estimates since I've heard around 50 of their songs much of which I did not appreciate when my dad was singing them (lousily) when I was a child but do now. I think any recognition they receive is justified and every one of their members had a fair say in the songwriting.
I would agree with some of the others who have posted here that U2 are overrated. I like them very much but not only did I not hear about them until 1995 but I never really appreciated them until 2000 and they had been around for quite some time. Their best songs pre-1995 have no place in my memory