rehv,
You could go with a BABY red eared slider for a 10
gal tank. Granted, you will need to be prepared to move it o a larger tank, because it will get bigger with time. I have two babies (1 yr old each) in a 20
gal long tank, and they will have to be upgraded soon.
I have a couple of things that I think should be braought to your attention though if you plan on getting one.
For one, dont use aquarium gravel. It is too small, and alot of times, the turtles like to pick thorught it, looking for food and such, I have small river rock in my tank. And, they do make aLOT of waste, so don't put down a lot of gravel.
Secoind, your regular tank hood probably isn't going to do good for you. Turtles need heat (around 90 degrees) from the light source that you do provide them so that they can get a chance to FULLY dry off at times. Not havingthis heat can cause things like shell rot, pneumonia, vitamin deficiencies, and other things.
Hm...that is all I can think of now, but I'm sure more will pop up later in my head. When they do, I'll repsond again. If you have any particular questions, you can send me a PM, or email, I'll be happy to helpo you if I can.
Turtles are my thing ya know, (hence the name) so, I will try and talk you into it....