These really have been interesting articles, thanks for doing these! IANAD, but here are some take-aways I've made after reading this.
1) "D&D" clearly in the logo. In the same way I don't have an Advanced Micro Devices processor in my computer, I don't play Dungeons & Dragons. I have an AMD chip, and I play D&D. I like the logos where "D&D" is clearly readable in the design, even if it's not obvious at first glance.
I noticed all of the designs I like, D&D can be read in the logo. The 3rd and 4th edition logos, #5 and #9 are the best representatives.
In a lot of the other logos, the ampersand is too big compared to the rest of the text. I guess it winds up seeming like it's own "thing" instead of linking the dungeons and the dragons. I dunno exactly. But the larger Emi made the ampersand when compared to the rest of the lettering, the less I liked it.
2) 2 lines. For similar reasons as #1, I was not as fond of logos with "Dungeons & Dragons" on a single line (1E, #8, #17). #10 is kind of an exception; still not a favorite, but there's something in it I like.
3) Small caps over lower-cased letters. Didn't like the 2E logo when I played it, still don't, and now I know why.
4) Red. Yeah, it's weird, and I probably never would have noticed it had you not called it out, but the logo needs red in the lettering. Or at the very least, none of the non-red alternatives presented come close to seeming like a decent D&D logo. Won't discount the idea that a non-red logo could work.
Gotta throw out another exception for
#10 the white on black aged lettering could be an acceptable alternative to red. Still not a fav, but I kinda like it. The red outline in #7 also works.
All IMO of course, and only after a few minutes of reflection.