What are some plants that are cool looking, and very hardy, as in, I can forget to water it for a week or two, and then after a couple of waterings, it will be fine, and its ok if the enviroment varies from shade to some sunlight and also lamp light. No flowers please, unless theyre green or black. And I need them to not be TOO big, so that they can fit on a table or desk. I want to keep this in my room. I guess a hanging plant is ok too, as long as its not that big.