It's been a while since I last did one of these but now my groups have changed a bit.
So, all my favourite groups go into 4 tiers. Number 3, then number 2, then number 1 and then my ultimates.
Tier 3: SNSD, Pink Fantasy, N.Flying, The Rose, Rocket Punch, WJSN, Bol4
Tier 2: TWICE, Loona, Red...