This is very difficult.
HTDAAB has more memorable melodies and choruses, overall I think the songs are actually better crafted. I don't know why but they are more instantly great and just amazing songwriting. They are at a more classical level of production and songwriting.
NLOTH however is more exciting of an album and more experimental (and successful at that) with the songwriting and production. It feels fresher (and that's not because it's brand new). While NLOTH doesn't have as many memorable melodies and choruses Bono's lyrics here are far better than Bomb, and that's a big deal in my opinion.
I would change the word "memorable" in your post for "catchy". HTDAAB is more catchy. NLOTH isn't. What doesn't matter since it's their best album after JT and AB imo.