It's always a strange one this topic.....to me this question is more of a combination of the below:
Overrated = Which popular bands, don't you like? Or is it that you'd just dislike the genre?
Underrated = Can you pick some obscure or little known bands, that not many have heard of, or some which were not popular enough to make it further?
Bands being extremely popular, in the context of their genre (or appealing across many genres), does not make them overrated. You might not like them, but your opinion probably goes against the norm (others ratings who like that genre).
Some of the popular bands I like mentioned as overrated on this thread are:
Nirvana, Pearl Jam, Foo Fighters, Led Zep, Muse, Radiohead, Metallica, Oasis, Arctic Monkeys, Kasabian,
One thing about most of those bands though, is I mainly liked their earlier stuff more, and seen most of them sell out loads of festivals or be absolutely rammed when they were headlining.
Most of the others mentioned on this thread as overrated have maybe one or two songs I like, but usually dislike them as a whole, as they're not in the genre's I like.
There are quite a few on here I've not heard of either, but that doesn't mean they are underrated, it just means that to me they've not yet been popular enough to get a rating (possibly as they've not had exposure, as they generally would not be rated highly, by the masses). Most bands I hear first are from nights out, or through other mates playing songs etc. I don't try and find obscure bands.
Some bands that I just couldn't get on with:
Ramones/ Sex Pistols - Awful, but I largely dislike the genre, I know about 10 people that have Ramones shirts who maybe like/ know one song at the most
The Beatles - didn't see what the fuss was about, but I'm deffo in the minority on this
RHCP - some of their singles are ok, but they've never impressed me live, and I've seen them a few times
U2 - one or two good songs, in the early days, but the latter stuff I really didn't like
Coldplay - a few great songs in the early days, but then it just got a bit boring for me
Stone Roses - Considering they were around 20 years, I can only think of about 3 songs I think are good