The Monkees often rendered their name in the shape of a guitar–you can see an example here.
And it looks like this.
Godsmack used that distinctive star/sun thing. Whenever I see that anthropomorphic sun I always think Sublime, but I don’t know if it’s their “symbol,” per se.
The band !!! is pronounced “chick chick chick” or “ch’ck ch’ck ch’ck.” It was supposed to be the noise made into a microphone during a quick sound check. If you catch them on a different day, they might say it’s a paradiddle on a closed hi-hat cymbal, or some other thing. Hell, they probably don’t even remember where it came from. 
Traffic always had a symbol of interlocking curved arrows on their albums. It was often very subtle (On this one, you can see the one band member pointing at it) and quite small, but it can be seen on all their albums.
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Heh. And now you have a pretty good idea of what my binder looked like in jr. high and high school.
I guess Sunn 0))) 's name counts.
Einstürzende Neubauten
The symbol on the left side is often used for Duran Duran
Wow, that’s a really bad symbol.
Not mentioned so far is the Abba logo with the backwards ‘B’ (which makes the palindrome band name also symmetrical), though that is probably more of a literal symbol.
**The Residents ** have a tuxedoed-and-top-hatted giant eyeball (or two, or three, or four). The outfit doesn’t change, although the number of such figures does.
Geinoh Yamashirogumi have a triangle thing.
Biohazard has theirs.
Bachman-Turner Overdrive has the gear with the initials B.T.O. and maple leaf which has come to symbolize them.
**
Electric Light Orchestra** has the huge space station or mother ship or whatever that is.
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Boston** has the huge guitar-shaped flying metropolises .
I thought Rush would be at the top of the list.
It’s a ridiculously overdone image of it. This is a little more like it.
