Just to put in my 2 cents. I've got a 10G low light, no C02, weekly Flourish doses.
The plants I've had luck with are anubias, marimo moss balls, and water wisteria. I've had no luck with java ferns or java moss, and bolbitis heudelotii looks too much like java fern to me.
skindy gave you a good list. I wouldn't recommend banana plants though. The cute banana-like tubers shrink as the plant uses up the nutrients in them and they like to shoot up long leaves to the surface of the water. Sounds like more maintenance than I want but it may be something you'd be interested in.
Also, crypts and water sprite are often recommended for low light, low tech setups. No experience with these.