Welcome to the forum @erdongdatian.
Fancy serial numbers are just a small part of notaphily. There's so so much more that collectors look for when collecting. The history and artistry are what fascinate me. As far as which serial numbers are more popular or valuable will become apparent once you've been collecting a while.
I’ve noticed you’ve asked this same question on several currency forums and was curious if you’ve found any answers that satisfy your curiosity.