There are tons of things to choose from:
Floating plants,
Plants that grow out of the water,
Plants that flower,
Plants that reproduce quickly,
Plants that need high, low, medium ligh,
Plants that you can break at the roots and replant,
Plants that send out runners,
Plants for breeding
And that's not all! Many people actually keep aquariums for plants, not fish. It all depends on what you feel like keeping. Just search on the internet for various types of plants. There are so many types to choose from!
Oh, by the way, you have to also include what type of lighting you have and what fish you have (esp. those that eat plants, like snails and silver dollars).
