That’s not exactly true for the Who. Besides a lot of R&B, like blondebear mentioned, they did art/power pop (heck, they were one of the founding bands of power pop, think of all the singles from 65-67), rock operas and fiddled a lot with synthesizers, all of that unthinkable in the AC/DC canon. AC/CD’s most untypical song is “Ride On”, because it’s slow, but it’s a sleazy blues at least.
Yep I agree that AC/DC is a better choice than The Who.
My main point was that either were a better archetype than Cream or Led Zeppelin
I wouldn’t consider The Who because although many of their songs were hard rock, many others weren’t, especially later. In particular the rock operas have songs in a wide diversity of styles.
Tough question. Still pondering it. Jeez, can I nominate Boston? Or do they have too many ballads? Blue Oyster Cult? Lots of good choices here already. Stones, The Who, how can you argue with those?
As much as I love to see The Top thrown out there, I gotta disagree. They a Little Old Blues Band from Texas. That Rocks.
But why? The blues is the foundation of all hard rock, and without blues there were no AC/DC, Who, Led Zep and all the others that have been mentioned so far. In my book, ZZ Top always have been a hard rock band.
Just wanted to say that that’s maybe the most accurately concise description of Zep’s sound ever. (well, yeah, more their earlier stuff)
To my ears, I’d say that even their most (IMO) roundhouse of a number - La Grange - has too much leathery Texas blues to slot into a strict hard rock thing. Back in the day someone mentioned the Eliminator album being pretty heavy, when I though it was basically Top 40 rock. YMMV.
Blow my mind on the Bubble Puppy mention!
Always loved the rockin (arabic?) guitar licks kicking off Elizabeth.
I’d go with with Sabbath, but maybe a bit too proto-metal, so, for pure, dirty, hard rock, I’ll go with “Young Man Blues” off Live At Leeds.
oh waitwaitwait - band, you want? Well, they’re filed under Noise Rock, but I thought Rapeman rocked harder than anyhting I’ve heard.
“Big Balls” might not exactly rock the hardest.
Check out the mastertrack of such sounds, The New York Rock and Roll Ensemble on “Studeao Atlantis”
Mind further blown - how come I’ve never heard of the New York Rock N’ Roll Ensemble before?
Interesting - about 30 seconds after where you cued it, indeed (good find!), that exact same “Elizabeth” riff pops up (or about 3/4 of it, anyway). Heh.
Is it too late to suggest AC/DC? 
Growing up the '70s and '80s, I was also a fan of The Angels, who are sometimes placed in the Pub Rock genre in Australia, and who rocked pretty hard in a lot of their songs. I believe that, due to trademark or possible name-confusion issues, they were often marketed as Angel City in North America and other foreign markets. They’re not AC/DC, but I think they were pretty excellent.
Heart.
I’m a big fan of The Who & they did initially come to mind, but I’m not sure I’d say they typify hard rock because they have a lot of songs that aren’t. Certainly many of their songs typify hard rock, though.
Bless yours
Oh have a…
Speaking of them, other than “Barracuda” and “Sing Child Sing” - which certainly had some heft to them - I’m not sure how hard they really rocked, especially later on in the coffee-commericals-as-well-as-david-foster-penned-ballads stage.of their career,
I’m all ears if I can get the title of even one more of their songs that one would consider rocking hard.
ETA: Ha - ok - “Crazy On You” could be considered a solid rocker, for sure…Anything else?
Please People.
Iron Butterfly
Seriously though, I have to go with Deep Purple.
AC/DC was also the first name to pop into my head, even though they probably aren’t even in my top 5 favorites when it comes to hard rock.
I loved AC/DC since they first came out definitely consider them worthy of being representative of hard rock. They have had a great run.
But I don’t think less of the Who just because they are not solely hard rock. They were masters of hard rock and the rock star lifestyle, but were talented enough to be successful in other areas. I don’t believe that’s a negative, and that it does in fact showcases the talent of the band. I saw AC/DC about 5 years ago and they still rock every song at their advanced age and that is quite a feat because the Who can no longer really do that.
But I have always preferred a mix of hard rock, blues and ballads to round out a set instead of just going balls to the wall on every song. Perhaps its a generational thing defining hard rock and what it means to be a rock star. Recent generations seem to want something that is in your face right from the get go and are impatient with songs that start smoothly and build up to a crescendo and then back down again and then back up an even bigger crescendo. That requires talent from the band and some patience from the listener. The Who have that going for them and IMHO that makes them a better hard rock band.
I’m don’t know who was first or best. The band that typifies hard rock is AC/DC.
The Cult - certainly post ‘She sells Sanctuary’
Thin Lizzy - try out the Jailbreak album
Queen - did plenty of hard rock numbers and quite a lot else too
Extreme
Ritchie Blackmore & Rainbow
Whitesnake
Aerosmith
Ten Years After
ZZ top
Def Leppard
Free
Alice Cooper
Gun ‘n’ Roses
Saxon
Deep Purple, AC/DC, Led Zep. Not necessarily in that order.