I have great luck with Dracaena Janet Craig Compacta. It is small, and stays pretty small overall. Does super well in low light, and doesnt need to be fertilized. It also does really well with dealing with being damaged and not dying but just bouncing back. Oh yeah, and they are super cheap around here... Always nice if it does die that you dont need to spend more then $2 or $3 to replace it. (although I have kept this type of plant for years not in a tank and I have a black thumb but i have never killed one of these.)