I stan many, but I'm going to name my 3 favourites:
2nd gen:
2NE1 - even though they disbanded you can still feel that they're a group and they keep on supporting each other โค
Minzy and Bom have gone solo, while Dara and CL are not able to because of YG (hope that they can leave the company asap)
I can recommend their songs if needed!
3rd gen:
Red Velvet - so called 'the most musically interesting girl group' of the 3rd gen. I love them with all my heart just like 2NE1! Many people say that they lack chemistry, but it's because they don't like skinship, but after watching some videos you'll be able to see how close they are to each other
They've just had a comeback which is the 2nd part of their 'ReVe Festival' trilogy (Sadly YouTube has been freezing views for 2 days now). I can recommend some of their best bsides, because they're also called 'the queens of bsides'!
4th gen:
ITZY - they've just debuted, but there's something that makes me feel like I want to follow their career. Probably their F(x) and Red Velvet's vibes
They don't have that much of a discography, but it's because they haven't been out there for long. I can still recommend my favourites
Hope you'll check them out. Have a blast
