10 Gallon Fish Help! Please!?

I have many 10 gallon tanks, #5 is defiantly off the list bettas Wont go good with ANYTHING, i think that #2 and number 3 would go great, if your interested in having baby fish without really doing anything 2 female guppies and two male guppies would make alot of offspring in short time. and the offspring are easy to take care of and you could possibly sell them to local stores.