Not to discourage you from chameleon keeping, but if you even need to ask this question, i dont think youre ready to own one. I'm not trying to be a jerk, but it takes a lot of time and effort to care for a chameleon that even a bearded dragon doesnt require, and believe me, i have had both. My chams took a lot more time every day to make sure everything was perfect, my dragons i can just throw salad in there and make sure theyre eating and basically forget about them. You cant do that with chams.
I applaud you, though, for asking, because thats a step in the right direction.
As far as ease of care and maintenence, go for a leopard gecko, ive kept and bred them, and frankly theyre one of the easiest and least expensive lizards to care for that was ever bred.
You could also go for a crested gecko, they dont even need a basking site.
Just my $.02.
Jamie
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Jamie A. Stine and the Gang:
1.1 Bearded Dragons (Lancelot & Guenivere)
1.0 Giant Frog Eyed Geckos (Peanut Butter)
0.1 Borneo Short Tailed Python (Ezmerelda)
0.1 Red Tailed Boa (Buffy)
1.0 Short Tailed O'possum (Jethro)
1.0 Greyhound (Hank)