I have 20 gallon tank with one damsel and a peppermint shrimp. I plan on getting clownfish later but not quite because of there price. What could I put in here that is easy and cool?
Oh boy, that is like asking 1,000 people what kind of candy tastes best. Or what kind of car is cool. You're going to get 2,000 different answers for different reasons. Maybe look at the myriad of websites with saltwater fish info and pick some out that YOU think look cool and then ask the forum if they are compatible with each other or easy to care for.
Not trying to flame you or be rude, that is just such an objective question!