ETH... and a few others. I'm going to have to disagree with you on this one for sure.
I have played guitar (and several other instruments) for over 20 years in various bands. I studied classical guitar under Christopher Parkening. I have played and recorded rock, jazz, classical and country music for most of that time (and even dabbled with some flamenco). And let me tell you that for rock bands, RUSH are one of the most talented group of musicians to take the stage. Neil is phenominal on the drums and a helluva lyric writer (and author too! reading his Ghost Rider book as I type this), Geddy is an awesome bass player and vocalist that at times is using nearly every appendage and his voice all at once, and Alex is a pretty decent rock guitarist.
In music, there is no such thing as THE BEST. Art doesn't work that way. But almost anyone with an ear for music can tell where much talent lies. Whether or not you like the music of Rush, they are VERY talented musicians and respected and admired by MANY musicians -- many of which you may listen to and respect. There is no three-peice rock band that makes a fuller sound than Rush does. And music is subjective, so you can argue about whether you like them or they are a "good" band in your opinion. But just trust me on this, any band that YOU think is a good band, when asked whether or not THEY think that Rush is a good (or great) band would mostly likely say "YES". A much higher percentage of Rush's fans are musicians themselves than most other Rock bands. You either seem to love them or hate them. But there's no denying the talent required to perform their music.
Edited to add:
YES!!! I bought Rush In Rio in both DVD and CD format the day it was released. Love it! Saw them on that tour in Denver and out of over 30 live acts that I've seen, that night was BY FAR the most magic. It is nice to be able to see the DVD and relive that night. Yeah, those crazy Brazilians are noisy in the mix, but I like it. It was neat to see 40,000 crazy fans (and 60,000 in Sao Paulo) at a Rush concert instead of waiting to see Brittney or Justin. Rush was here long before they came, and will probably be here long after they are gone. Rush is something like number two on the all-time rock band gold album charts behind The Stones. And yeah, it is because of them still being together after all these years just like with The Stones. Although with the whole Keith and "Sir Mick" deal, maybe Rush will pass them up...