Top five weight classes by global popularity?

[SlySlickSmooth]

You can intertwine two weight classes if you have to.

I'd put 140/147, 168, 175(maybe combine with 168), and the Heavyweights in the top 3/4 for sure. What would be the other popular weight classes?

[sugarsmosley]

The money division for a while has been welterweight.

least popular divisions, below bantamweight (118 lbs)

I'd say light welterweight has been hot, with middleweight following due to the likes of sergio and GGG.

interest in the heavyweight division has fallen off recent years

[Jloro]

I like WW JMW MW SMW LHW in no order

[sugarsmosley]

I like WW JMW MW SMW LHW in no order

No love for the straw weights? SMH!

[Biolink]

Ww
mw
smw
hw
fw

[Beercules]

130 might shape up to be 'hot' soon.

140-154 are the most popular now and have been for the past couple of years.

160 is popular also