What follows are some notes on the covers I submitted for the top Golden Age Covers Contest over on the forums (a surprisingly Hater Free zone 🙂 ) These are REALLY off-the-cuff. I know you guys won't hold that against me.
I'm starting from the top down. Why? Because it's more fun for me if I do that.
1. Weird Science Fantasy #29
Only the most dedicated contrarian would argue against Frank Frazetta being one of the most talented artists to ever work in comics. What he accomplished in his short time in the industry was remarkable. Of course, what he went on to do when he left for greener pastures was far more impressive- he became a true legend in his field and went on to inspire and influence an entire generation of artists.
What does that have to do with WSF29? Well, for my money this image is the purest comic book expression of the Frank Frazetta that the world would come to know in later years. This drawing compares favorably with anything in his entire oeuvre in terms of the kind of raw power that makes Frazetta "Frazetta." He has an uncanny knack for capturing a freeze frame moment of savage action and that knack is in full display here.
Of course, beyond that, it's just a cool-ass drawing, inked beautifully. Frazetta was the best pure inker in comic books in his time and this cover shows ALL of his inking chops brilliantly. I especially like the intricate, sinewy musculature; the craggy, perfectly delineated rocks; and the patches of wonderful, Raymondesque feathering.
All in all, just a masterpiece.
2. Spirit #22
Eisner created some of the greatest femme fatales in comics history and this image represents the very essence of the archetype that he knew so well.
In other words "She's sexy, but she's got a knife!"
One thing I really like about it is the bold contrast in the image. She's lit by what might as well be a spot-light from two angles which creates bright white highlights and a pool of black that runs down the center of her figure. It adds weight to her form and created a decidedly cinematic feel.
3. Startling Comics #49
Schomburg + airbrush= one of my favorite things in comics. This cover is a perfect example of why that is: it's beautifully rendered with a primary color palette that screams "Golden Age;" it's got a damsel in distress in bondage (another GA hallmark); it's got that dimensional "airbrush" feel; and it's got a FREAKING ROBOT front and center.
As we all know, robots rule the school.
4. Weird Science #16
This one is a really personal choice. 
For starters it's Wally Wood and I love Wood's art. He's probably my favorite of the EC regulars for his EC work(when I consider the breadth of Al Williamson's career he takes over the top spot) Something about Wood just works for me. Here everything does: the kids, the dog, and especially the aliens just have a certain spark that brings a smile to my face.
Another thing that I love about it is the subject matter. It's got such a 50s feel to me- big head aliens in glass-dome helmets landing here to take over the world. That's some cool stuff right there.
Finally- I just love the Sci-Fi ECs. I devoured them when I was a kid and still love them to this day.
5. Man O'Mars #1
No logic behind this one. I just love the image. It's a neat drawing and the coloring is so garish and strange I just can't help but like it. Everything is all purple and green and freaky. Too cool.
I actually own a copy of this as well, which has to count for something.
Right?
It's interesting that this is the only Fiction House book I voted for. I love Fiction House books more than any other GA publisher besides EC. It's strange because the overall level of their covers was so good. There are really no singular standouts in my mind.
Odd, that.
6. Thrilling Comics #63
See my answer for Thrilling 49 and swap out the robots and the bondage for a jungle girl and a big cat.
I'm a sucker for jungle girls and big cats on comic book covers.
I like the rendering on this cover more than the rendering on the Thrilling cover, by the way. This is really some sweet airbrush work.
7. Suspense Comics #3
Nazi Clansmen + Bondage + that crazy blue and red color scheme = crazy cover.
8. Reform School Girl #nn
There's a part of me that thinks that this is the greatest comic book cover of all time. Obviously, it's not, but there's so many crazy things about it the part of my brain that thrives on the outrageous desperately wants to throw caution to the wind and make the claim.
I'll tell you on thing, I wish I were old enough to have had my youth damaged by seeing this lurid cover on the newsstand.
9. Mister Mystery #12
Brazen cruelty! Right there on the newsstand!
An image worthy of Takashi Miike.
10. Crime SuspenStories #20
Nothing fancy, just a straightforward, close-up rendering of a hanged man. It's that direct, unadorned approach that makes it work so very well. Of all the EC covers this might be the one that sticks with me the most.
Plus, ECs rule.