Pyxies all the way! My Vanessa has a ton of personality. She's probably as big as she'll get at about 5". She has a phobia of thunderstorms and has refused hand feeding since the time she caught my finger. (Someone one suggested that Vanessa is trying to protect me, but I think she just didn't like my taste.)
Id go with the american bullfrog because its the most active and none of the frogs are going to want be held so you my as well get the one thats going to be the coolest to watch unless you want a colorful one.