Bit of a range when it comes to artistic skill and page layout, eh? I was a kid; what did I know about that kind of stuff? No, my criteria for a "favorite cover" was -- are you ready for this? -- whether or not there was a full-figure character on it suitable for cutting out.
"Wait -- did you say 'cutting out'?"
Yup. I actually still have most of the comics from when I was a kid, but many of the covers are gone because I ripped them off and cut out the figures.
"In the name of all that's holy, why would you do something like that?!?"
Well, those were my "action" figures. I only had a handful of those super-cool Mego figures, so I resorted to the two-dimensional artwork on the covers of comics. Each figure was limited to one pose, but a handful of comics could yield all sorts of different poses.
"Why the covers, though?"
A few reasons, actually, of them entirely practical. First, the cover was of a better stock of paper than the interiors, so they'd last longer. Second, all those panels in the story meant that the figures were smaller and frequently incomplete. The cover was often the only place you could see the full figure of the character. Third, because of the way DC at least designed their covers, they didn't tend to do a whole lot in the fore- or backgrounds; everything was placed in a conveniently middle-ground area. Which meant that many of the figures were roughly the same size.
Besides, back in the 1970s, where else were you going to get Zan and Jayna action figures? Superman and Batman you could come by; Saturn Girl, not so much.
When I was a kid, I enjoyed my comics. I got hours upon hours of fun out of my 20 or 30 cents. And, you know, that's why I dig comics -- not for any collectibility or investment or anything. But because I enjoy them. Nothing against those who do have other reasons for getting in to comics, but I just want be entertained.