White's Tree Frog (Litoria caerulea). They are extremely easy to care for, very hardy, long lived, feed very well (almost too well) and have a friendly cute disposition. For these guys a 20tall is adequate for 1-2 individuals. I would also recomend African Clawed frog (Xenopus). These guys are fun too watch, long lived, easy to maintain, hardy and very cool looking. Another species I would recomend is Bombina orientalis (Oreiental Fire-Bellied Toad). Very hardy, long lived, captive conditions easy to meet, brightly colored and work well in groups (5 gallons per toad). Hope this helps!