Lovely topic, Rob.
I canāt recall who was mentioned on the video Stitch posted, but the name that I missed when seeing Robert Johnson was Son House.
From late 60s, Peter Green worth a look. You can take in the early Fleetwood Mac as well as John Mayall recordings.
More modern, what about Billy Gibbons. Perhaps ZZ Top not always pure blues but the blues is strong in them when not going too commercial.
This is a great topic.
Couple more thoughts: in classic acoustic blues/folk: Lightninā Hopkins and Mississippi John Hurt are fantastic. Also Skip James, Rev. Gary Davis and Big Bill Broonzy.
In the non-guitar category: Professor Longhair (New Orleans-style piano) is great. And, what the heck, Louis Armstrong. Some would say that āWest End Bluesā is the absolute pinnacle of American music.
I would add to your 70s+ The Allman Brothers Band when Dwayne Allman and Barry Oakley were still alive. Live at Fillmore and Eat a Peach are great albums and if you can find it, listen to Duane Allmanās version of Going Down Slow from the Anthology album. Or, for that matter, the entire Anthology album which is comprised of takes from the Muscle Shoals studio when he was a session player there.
For 70s+ Walter Trout.
Thanks David, know ZZ top well but trying to keep this to straight blues rather than rock with blues influence, all those (Zep, Cream, stones, Hendrix etc) I am fairly familiar with already!
Interesting band, not one I know a lot about, was going to āwrite them ofā as a blues influenced rock band (with some folk, all very 70s) but a fair number of their songs seem solidly rooted in blues. Still think they are more in the rock w blues influence branch of music
You need to check out Albert Collins - AKA the Ice Man - for some solid chicken pickinā! Classic sound.
Paul Butterfield and Mike Bloomfield also should be on your list if you havenāt known them already.
Also Elmore James, Otis Spann, Mississippi Fred McDowell, Skip James and Johnny Winter along with Jorma Kaukonen/Hot Tuna.
Kenny Wayne Shepherd comes up with some awesome riffs. Iād start out with the āTrouble Isā album: Trouble Is... - Album by Kenny Wayne Shepherd | Spotify
Some good stuff, I think I could make a very good playlist out of everyones versions of āThe Sky is cryingā! (actually some of the bending Walter does on that is insane)
Still working through all this homework so keep em coming, Iāll try curate the list at somepoint
or blues with a rock influence 
I guess at some point this becomes shades of grey rather blues or rock.
My favourite Hendrix album is titled Blues. A little different to the stuff he is probably best know for.
Similar with Gibbons, you can probably find specific songs, maybe an album, when the music is closer to traditional, dare I say āpureā, blues.
For the Stones you could listen to Blue and Lonesome. All covers but perhaps interesting to hear their interpretations record in the 2000s.
Similarly, I enjoy listening to the original Robert Johnson and also Claptonās Me and Mr Johnson, which is perhaps easier on the ear.
Yep its all grey area really, well blue ā¦ 
I think in here Iām more interested personally in the more mainline pure blues
Iād add Gary Moore and Albert Collins.
Gary is a great guitarist but just dont connect with his music overall, Albert for sureā¦!
@DarrellW posted a couple by Joanna Connor, and then @Dave911 added this one What are you currently listening to? - #225 by Dave911
That is some amazing blues. The woman can play, and she sure can sing. Joe Bonamassa produced her most recent album on his independent blues record label Keeping The Blues Alive.
I listened to an interview with Ian Paice (Deep Purpleās drummer) who was in Gary Mooreās band during in a Purple hiatus. He mentioned that Moore didnāt consider himself a blues guitarist and felt painted into a corner by the success of the blues record. He wanted to continue down a rock path with various influences.
Heās certainly got the blues but does a lot more, which is totally fine, you wouldnāt say he is a just a blues guitarist tho.
For sure, Rob, and I think he aspired to do more than just the typical hard rock rhythm and lead. But despite efforts and his considerable ability perhaps never achieved fully those aspirations. Perhaps also plays into the under-rated debate, why some consider him to be one of the greats and others consider him to be very good but not in that great and influential league.
And when we think of blues it gets interesting in terms of who is ājustā playing the blues well vs who may be evolving the genre, doing something different that would still be considered blues.
For the former I guess one can then decide who you listen to and players from one generation to the next will not be significantly different, if one is trying to deepen an understanding and appreciation for the blues.
And just in case, without scrolling back ā¦ are Keb Mo and Taj Mahal on the list?
I would add:
Albert Collins
Bonnie Raitt
Canned heat
Lowell Fullson
Luther Allison
Memphis Slim
Shuggie Otis
Sam Chattmon
All of them great blues musicians, well worth listening to!
I donāt know how much they are up your alley, but you may be interested in Professor Longhair, Allen Toussaint and Dr. John as well.