For a totally different direction, I’ll suggest Kraftwerk, Yes, Roxy Music.
Are you sure?
Someone out there must like it. Lou Reed, at least. Maybe.
Lester Bangs certainly did.
Also Jerry Jeff Walker, specifically this album.
You may already be familiar with some of these, but:
Be-Bop Deluxe, Sunburst Finish – power pop
Mott the Hoople, Mott – glam rock
Traffic, The Low Spark of High-Heeled Boys – groove rock
King Crimson, Larks’ Tongues in Aspic – art rock
Gong, Flying Teapot or Angels Egg – art rock
Al Stewart, Modern Times or Past, Present and Future – folk rock-pop
Strawbs, Bursting at the Seams – prog-folk-rock
Like would be a strong word for how I feel about MMM, but I’ve heard all 4 sides. It’s got it’s moments.
In the country vein, I can recommend Townes Van Zandt. Live at the Old Quarter, Houston, Texas is his most reliable listen, I think. But, it is a live record of an acoustic act. It has crowd noise (murmurs, clapping along and such), and it’s a bit more hardcore country than Parsons’ work, but it is from the 70’s, and beautiful. If you like that, there’s a lot of other good songwriters and performers from the same scene.
So, now that you know that about me. How about T. Rex?* Electric Warrior was great, possibly the greatest Glam Rock ever, if you don’t try to take it seriously. The Slider is made of the same stuff.
*Yes, the mildly dead album tracks that should have been singles thread made me think to mention 'em.
Nick Drake was my immediate thought, as well. Pink Moon being the obvious album. Just a man and his unique acoustic guitar stylings (with the occasional piano). Soulful, meditative, mystical, a bid sad. This is one of the must-listen-to albums of the 70s.
You might also enjoy Serge Gainsbourg’s Histoire de Melody Nelson if you don’t mind a kind-of “dirty old man” French music. Still pretty mellow; great melodies, orchestrations, and sexy.
I was also going to mention Scott Walker’s Scott IV, but that’s 1969. If you haven’t heard it, you should.
If you want something a little more rocking, I’ve got a few to start you off:
Television - Marquee Moon
Buzzcocks - Singles Going Steady
Joy Division - Unknown Pleasures
The Clash - London Calling
Todd Rundgren - Something/Anything?
Warren Zevon - Warren Zevon
Warren Zevon - Excitable Boy
Two of the best albums of the 70’s.
If you like live performance albums at all, I’d suggest giving **Waiting for Columbus **by *Little Feat *a try. For my money, it’s the tightest live album ever.
Hah, pulykamell, we have a very similar taste in music, I noticed it before. I was going to recommend Singles Going Steady and Marquee Moon as well, but refrained because the OP mentioned that they got punk/new wave covered. But now I might as well throw in some more suggestions in that vein, try Crossing The Red Sea With The Adverts by the Adverts, all albums by the Undertones, the first four by the Stiff Little Fingers and Australian punk, (I’m) Stranded by the Saints.
Yes, Television’s Marquee Moon is a perfect, wonderful album.
Heck, if we are venturing outside Country Rock, you would have to listen to Big Star’s music - the first two albums are offered on 1 CD. The great music and sad story of Big Star is well known to music geeks and their work still sounds wonderful today. When I hear Mod Lang, Back of a Car, She’s a Mover and September Gurls I just love it.
You know, I actually glossed over the early punk/new wave stipulation and just saw the “no disco” in the OP. Regardless, in case the OP has a hole in their collection, we have our recommendations out there. 
Oh, yeah, Big Star is a must, too. I would also suggest the Modern Lovers self-titled album. If the OP wants to dip his toe into a genre known as “Krautrock,” the Kraftwerk recommendation is great, but also try Neu! (they are all, hypnotic, instrumental records. I’ll go with Neu! 1 as the album to start with, but I like Neu! 2 and Neu! 75, as well.) If you like the band Stereolab, it’s worth listening to, as you’ll note the influences on them. Also, Can’s Tago Mago.
Also, XTC’s Drums and Wires if the OP hasn’t gotten to it.
Oh yes, Big Star, seconded or thirded. “I never travel far, without a little Big Star”. The aforementioned # 1 Record and *Radio City * are essential for a 70s playlist, in fact the pinnacle of power pop, but if the OP is a bit more adventurous, they can also try out 3rd/Sister Lovers. Radically different, eerie and haunting, but very moving and ahead of its time. Check out Kangaroo, one of the weirdest but yet compelling songs recorded in that decade. And who else would call a pop song Holocaust, other than Alex Chilton?
As for your other recommendations, all seconded.
Yeah, #1 Record/Radio City are absolute essential. “September Gurls” is perhaps the perfect pop song, and “13” is the greatest song of adolescence ever written. Just brilliant music. Agreed on Sister Lovers, as well. It’s hard for me to pick a favorite from their (sadly limited) output.
It’s great to see the love for Big Star in this thread – a quick note, for those who don’t know: the 2012 documentary Big Star: Nothing Can Hurt Me is currently streaming on Netflix. I enjoyed it immensely (and it prompted me to purchase the Chris Bell album I Am the Cosmos – another good recommendation for those looking for quality but lesser-known stuff, btw).
I heard The Ballad Of El Goodo on the radio yesterday afternoon – it’s a top-5 song of all time in my book.
Awesome! Thanks for the tip. I know what I’ll be queuing up later today. 
Me, too! Thanks! And JKellyMap - cool, sorry I missed your mention upthread.
So I’m assuming you listened to the Flying Burrito Brothers, right? What about Doug Sahm? Steely Dan and early Chicago aren’t “lesser known”, but they’re damn good, and belong on any 70s playlist.