My personal favorite frogs to keep as pets are White's Tree Frogs (large and very friendly, and they're also really attractive little guys who always seem to be smiling) and Pac-Man or Argentine Horned frogs (QUITE large, not always very friendly, but extremely entertaining and funny-looking.....rather like a hockey puck with eyes and teeth)

If you want any more information on these or other froggies I'd be glad to help you out.