If you want a lizard that will just sit on your shoulder, a bearded dragon is great - but they don't do much else with people. SOME chameleons, while not friendly, will interact with you much the same way they'd interact with conspecifics in the wild. These behaviors are as close to being outgoing as you'll see in reptiles.
On the other hand, you never know if you're going to get one of those chameleons. Melleri, the most outgoing species, is not always like that. You may have a super easy to handle chameleon that will come to you as soon as you enter the room, trying to get close to you even though it's got food in the cage.... or you might end up with an evil spotted tree-deamon that also happens to be the third largets chameleon with a massive set of jaws...
I say, if you want a friendly chameleon, do some more research. Friendly ones are great, but they're not something you can count on actually getting! Want a chameleon first, then just "hope" for being lucky and getting a non-evil one.