Bought at the time:
Action Comics #458
Brave and the Bold #126
DC Special #21
DC Super Stars #2
Defenders #34
Fantastic Four #169
Justice League of America #129
Marvel Premiere #29
Marvel Presents #4
Marvel Team-Up #44
Metal Men #45
Plastic Man #12
Power Records PR-30
Super-Team Family #4
Superman #298
Superman Family #176
Superman Vs. the Amazing Spider-Man #1
Wonder Woman #223
World's Finest Comics #237

Bought later:
1st Issue Special #13
Avengers #146
Captain America #196
Doctor Strange #13
Kobra #2
Marvel Chillers #4
Marvel Double Feature #15
Hercules Unbound #4
Master of Kung Fu #39
Super-Villain Team-Up #5

As back issues :

Creepy #78
Kamandi, the Last Boy on Earth #40
Swamp Thing #22

1st Issue Special #13: Return of the New Gods. Conway, O'Neill, & Vosburg don't stand up to Kirby.

Brave and the Bold #126: An odd issue. Art by Aparo & John Calnan. Aparo's credited first, but he did the inking on this, not the pencilling.


Champions #5: I rather liked this team, mediocre though it was.

Defenders #34: I didn't miss an issue of this, ever (at least not after I started buying it at #4).

Hercules Unbound #4: I really enjoyed this series, inconsistent though it was.

Inhumans #4: I bought all of these, despite never really liking it.

Kobra #2: I was pretty excited by this one. It felt different.

Marvel Presents #4: I stuck with the Guardians throughout this series. I had the debut Marvel Super-Heroes issue, so somehow I felt I owed them.

Metal Men #45: I met this team when they were in reprints a couple years earlier, and always liked them.

Planet of the Apes #18: Probably the comic I most looked forward to each month.

Plastic Man #12: I liked Plas from the Jack Cole reprints. This...ehh...not so much...but I bought every issue.

Son of Satan #3: It was never the same after Trimpe left this. I didn't realize at the time that he was what made it appealing at the start.

Super-Team Family #4: JSA reprints? Of course I'm buying!

Super-Villain Team-Up #5: A Team-Up book with a twist. I was on board.

Superman Vs. the Amazing Spider-Man #1: This felt more historic than any comic I could imagine buying off the racks. And it didn't let me down.

Swamp Thing #22: Once my favorite, I was sticking with it.

Tomb of Dracula #43: Never let me down, I never regretting buying an issue of this.

Warlock #12: Starlin was blowing my young mind. Never ever appreciated his work as much as I did then.

X-Men #98: There was a reason this was popular. Good stuff!

As best I can tell I didn't buy any comics this month. Have since read quite a few.

Adventure Comics #445: Aparo's Aquaman plus the Creeper!
All-Star Comics #60: I loved the JSA and Earth 2.
Defenders #35: I'd keep buying this for the entire run.
Doctor Strange #14: I wasn't buying this regularly, but the crossover with Tomb of Dracula drew me in.
Freedom Fighters #2: I was excited by this series--a new team of Golden Age revival characters from another of the infinite Earths, but it wasn't long before I realized this was the most awkward, ungainly superteam ever. And the stories and art were routinely subpar.
Howard the Duck #3: I was thrilled that this was being published, but losing Frank Brunner (here replaced by the inappropriate John Buscema) was the beginning of a string of disappointments with this book.
Justice League of America #130: The JLA could still hook me, even with an unappealing cover.
Marvel Team-Up #45: Team-ups were an easy sell, even MTU, my least favorite. I think the unusual guest star, Killraven, made this one look more appealing.
Omega the Unknown #2: I was fascinated and a little confused. At this point, I didn't realize that these kinds of largely unexplained stories were typical of the kind of fiction I'd come to love the most.
Planet of the Apes #19: I was an Apes fanatic, and I was really digging Mike Ploog's work...less so when inked by Tom Sutton here.
Plop #21: This had really plummeted in quality with the amateurish look that the covers adopted, and I hated the new logo.
Secret Society of Super-Villains #1: This one should have been a lot better than it was; it never lived up to my high expectations.
Skull the Slayer #5: I was fascinated by this series, which seemed to change its premise every issue.
Tomb of Dracula #44: The Dr. Strange crossover worked very well. Wolfman succeeded in something that fans of the time thought might have been ill-advised.
Cost: 12 * $0.30 + $0.75 + $0.50 = $4.85, a great deal from today's perspective, even if there weren't a lot of standout comics. 
The "Chan Count": Ernie was credited with 14 out of DC's 32 covers this month. I feel fairly certain that he provided the layouts for Blackhawk #246, Freedom Fighters #2, G. I. Combat #190, Our Fighting Forces #167, Kung Fu Fighter #8, Weird Western #34 (at least; quite possibly more, maybe even all except Kubert's four covers and Plop!). Not quite as much blank cover space this time, but still enough to continue to characterize DC's overall look of the era.

Favorite Cover of the Month: Deadly Hands of Kung Fu #22, where painter Bob Larkin delivers a moody and well-staged White Tiger spotlight.
Comic I'd Most Like to Have: There's nothing I'm especially keen on, so I'd take Korg: 70:000 B.C. #6. I never sampled that series, and the cover looks good. Charlton wasn't producing their best stuff at this point, but I'm confident it would at least be interesting. 
Comic of the Month: Adventure Comics #445 : It was great having Aparo on Aquaman again--he was near the top of his game here, although I'd have still preferred the Spectre running in this slot.

Amazing Adventures (Killraven) #36 - loved this comic, only wish it had lasted longer.
Astonishing Tales (Deathlok) #35 - another fantastic but regrettably short-lived series
Captain America #197 - have never re-read it but I remember liking the Mad Bomb multi-parter and Kirby's CA comeback in general, though the character was never a particular favourite
Conan the Barbarian #62 - I believe this was the Steve Gan era? I didn't think the Buscema artwork got back on track until Ernie Chan came on as inker
Defenders #35 - an installment in what became known as the Headmen saga, possibly the highpoint of the Gerber Defenders
Howard the Duck #3 - great story by Gerber; I was sorry to see Brunner leave but the Buscema/Leialoha team produced some outstanding work here; in fact, Leialoha ranks as one of Buscema's best inkers for me, based on this single issue.
Incredible Hulk #199 - decent but not great Marvel comic of the era; I've always kind of liked Doc Samson.
Jungle Action #21 (Black Panther) - good stuff, though I like BP better as king of Wakanda than in a story about America's race problems. Excellent art by Bill Graham and Bob McLeod
Marvel Feature #4 (Red Sonja) - I was a diehard fan of MArvel's sword & sorcery line; good art by Frank Thorne
Omega the Unknown #2 - I was buying anything with Gerber's name on it; this was a very strange series but I had already been prepared by other Gerber series like Man-Thing, HtD, Defenders.
Savage Sword of Conan #11 - I liked the Yong Montano inks this issue better than Tony DeZuniga's in #10, too bad he never got any more work at Marvel that I know of
Strange Tales #185 - this 70s reprint series is where I first got to read the Ditko Strange; I was as deeply into these stories at the time as I was the then-current Englehart run.
Tomb of Dracula #44 - this crossover with Doctor Strange wasn't a highlight for either series but still high-quality stuff
Werewolf by Night #38 - this series really stepped it up once Perlin started inking his own pencils;

books I was reading but missed this month due to distribution:

Avengers #147
Doctor Strange #14
Skull the Slayer #5

didn't get to read any of them until years later.