Impossible to predict unless you're going with damselfish or clowns or other simple fish. Easier to work backwards eliminating the ones that are more difficult to get to eat anything. Also is this office tank fish only or reef and is it bare bottom or you have sand and how big is it? Stay away from dragonets as they eat primarily live pods and some are fortunate enough to get them to eat some frozen or pellets but really they need a pod enriched environment. Anthias can be tricky. Some wrasses are great with flakes but some aren't. The family of leopard wrasses can be difficult to eat flakes as are the Anampses family of wrasses but the fairy wrasses and other wrasses take to it readily. Tangs do well on flakes but depending on the tang they need more room. Angels do well but again are you talking dwarf angels or the larger species of angels and then if it's a reef they might enjoy also snacking on your corals. So take the size of tank, the tank environment and how you have it setup all into consideration and then work through process of elimination. And in all honesty all fish are different. You can have two of the same fish and they might gravitate towards different foods. In my tank which is a mixed reef I have five fish, two types of angels that fortunately don't pick on coral, a Damsel, a firefish and a sunburst anthias and they all eat flake