One thing that I really enjoy about the weekends in Taipei are the flower markets. As Friday approaches, they push the cars out of parking lots, then they fill them with plants and flowers. At the intersection of JianGuo and Xinyi, you can find one of the larger "flower cities" (
建國花市) in Taipei.
These flower markets host a range of plants from miniature cacti to full-grown trees. I prefer the smaller ones that I can put on a table or near a window. Actually, I don't like the flowers that much. I like the green plants, the ones that are help me breathe a little better. There are many plants that clean the air.
Having plants in your house provides many benefits. They provide a sense of warmth, living art in your house. They are aesthetically pleasing and nice to look at. If you have trouble being responsible, plants are a low risk way to learn how to take care of something (besides yourself). It's like a pet, but without the crying if you don't feed it, and no sadness if and when it dies. Like I mentioned before, they can help clean the air in your house or room. Living indoors, there are many things that can pollute the air: dust, paint, building materials, etc. In some cases, plants can reduce these things and make living indoors more enjoyable.
Depending on where you live, there is a flower market near you. I live in Banqiao so I will sometimes go to the market near Xinpu MRT station. If you are looking for something to do, you can go to the flower cities and buy some plants to spruce up your room.