I would say that it's either them, Floyd or Led Zep, but yes, they are the most iconic (shame its for the arena songs, and not the masterpieces like Innuendo, you take my breath away, keep yourself alive, spread your wings, these are the days of our lives, etc. There is more to queen than we will rock you, we are the champions and bohemian rhapsody)
No one will EVER perform better vocals than on these are the days of our lives. Watch the video and tell me that is not THE most emotional performance you have ever seen. Knowing he's dying horribly from AIDs, you can see how ill he is very clearly, and he still sings absolutely perfectly. The song is about him coming to terms with the fact that he knows he's going to die, it's heartbreaking, the video makes me cry literally every time I see it. I think Innuendo, their last album is the best of their career, and should be ranked more highly as one of the best rock albums of all time.