>>792177not sure if I would call them essential but they were popular when they aired and sometimes come up here and there
>Tiger & Bunny>Higurashi no naku koro ni (the DEEN adaptation sucks but I still have some nostalgia for it, best to read the VN first)>Mitsudomoe>Monogatari series>Black Lagoon>Hisone to Masotan>Houseki no Kuni>Hanamaru youchien>Paranoia Agent>Doremi>Paniponi DashAlso Dororo and Kemurikasa but those ones are more recent so who knows wheter they can be called """essential"""
I reccomend just watching whatever you like or interests you even if it's LN or shonen shit, taste is subjective afterall