Actual mega nugu/underrated groups?

I really want to get into more nugu groups after listening to some songs from nugu groups, i'm sure there are many out there with good music but are unnoticed

So my fav nugu boy group is Boys Republic and i really like their songs. Does anyone know a group similar to them? :"

I also prefer girl groups more i think but i don't mind if you recommend boy groups more ^{^}