Royal grammas and pseudo chromis are actually considered highly territorial, not aggressive. They generally act defensive only when something is within a short distance of their spot.
My faves:
Large angel, Imperator
Small angel, Coral beauty
Butterfly, Ranfordi (please don't buy these get my 2'nd favorite instead, Puntato)
Tang, Scopas
Clownfish, Tomato
Damsel, blue green chromis
Anthias, Lyretail
Goby, Large-Scissortail, small- pearly jawfish
Grouper, Miniatus
Lionfish, Volitan
Puffer, Dogface
Trigger, Clown
Wrasse, Harlequin Tusk