I find it really impressive on Tsunku's part that most people are not listing the same B-sides as their least favourite or top favourite, it kind of shows that he's writing a few different types that appeal to different people than some really good ones and some really bad ones that everyone would rank the same. If that makes sense.
I've seen people really hate E-cha E-cha and others list it as their first(It's my personal favourite, though I honestly like them all), same with Rock no Teigi and Itsumo to Onaji Seifuku. Even if the singles are closely related in style right now, album songs and b-sides are still all about variety with him.
Or at least that's what it feels like to me.
Also completely unrelated, but Haruna going through a random English obsession during the Making of (CD Jackets photoshoot portion) made me happy. She was working so hard to have perfect pronunciation. I swear she gets more and more charming