you could keep one or two anoles in a 10 gal (only one male though)......... they'd prefer a tank with height, but you could do it. they are cheap, and easy to care for for the most part. they only need gutloaded crickets and misting of the tank a couple times a day........... the hard part is, they need the uv light (and these bulbs can be expensive, though one will last you about 6 months before it is no longer benficial), and they need a heat light (but most lizards do).
you could also research house geckos, they are usually under $10 US. green tree frogs are cheap too, but like anoles, they are arboreal and would prefer some height, but you could get away with one in a 10 gal. they have more to their diet, but still easy to care for, and don't require a uv light as they are nocturnal.
a single leopard gecko COULD live in a 10 gal, though i personally would want to give one something with a bigger footprint.......... but they have special heat and light needs, as well as feeding. and they aren't always exactly inexpensive.
the best advice i can give is to go to the various shops where you live, write down the reptiles they carry that you like or are in your price range. then get online and RESEARCH RESEARCH RESEARCH. thats what i did, and continue to do when i see something new i like. there are some great reptile forums out there that have caresheets and the users keep all sorts of reptiles so you can read or ask about just about any type.