personally, I think bettas are cheap, cool, nice looking fist, BUT, if you keep MORE THAN ONE, make SURE they are ALL FEMALES. males will fight with other males and may even beat up females. I had a colony of about 15 females in a 30 gallon tank. They always seemed to just chill. The females are way less flamboyant, with shorter fins, but they get big and colorful but again not as colorful as the males. Bettas are kinda hard to kill though if u get past the new tank syndrome and their numbers make them cheap. Also, if you want, they come in a vast variety of colors. In my opinion probably the best begginer fish. second are zebra danios bcuz Petco has notoriously bad stock and 4 years ago i bought 10 of them and they are still there alive and well in my 30 gal. They zip around all over the tank all the time. really awsome fish too and cheap.