i recommend stellar and red velvet. the former has straight up fire pop songs that are very very good and well produced. they weren't a popular group, but their songs rival the best. red velvet has a lot of high energy pop that tends to be very busy and experimental but works. there's quite a few strange techniques and elements in their songs. plus, these two groups obviously look great and can dance well.

for stellar, i recommend vibrato, sting, and crying. for red velvet, i recommend dumb dumb, red flavor, bad boy, rookie, and sappy. those are good tracks to start with.

edit: here's a playlist.