I recently purchased my first chameleon... a veiled. Just about everyone agrees that they are the best starters. They are the hardiest. But don't be mislead though, they require a lot of time and attention and you should be doing as much research as possible.
Redundancy is a virtue..... most def, but i agree a veiled but if you are trying to use up a spare aquarium... get some pygmy's... the only type of chameleon that should be kept in a aquarium all others should be in a nice big screen cage or a free range set up...