In what regard? Power scaling? Utility? In general?
Awakenings can be a game changer also.
In general - Kuma's Fruit , Enel's Fruit , Kizaru's fruit , Boa's Fruit etc
Power scaling - Characters from pre skip area - Logia DFs specially pika and goro goro ni
From top tier perspective - Kaido's DF , WB's DF , Akainu's DF , Law's DF etc