Design? Function? Cost? Materials? How it matches your decor? What it does to your indoor air quality? I think all of these things are important. The problem is the latter is nearly never an issue for the average buyer, not unless your child has serious allergies and can be immediately affected by the off-gases that only slowly poison the rest of us.
Some of the factories we visited on our Cebu trip, which I won't mention, made the both of us feel like our heads were in a vice grip from all the fumes. We hope these companies will find a non-toxic alternative for both their workers and end-clients. In just a few clicks I found these solutions on the net, Aquaresin and Bioresin. I'll be sure to pass it on. It's our job as consumers and healthy beings to request and expect only ecologically and health friendly products and materials as the only option. Hopefully one day furniture stores and building supply shops will only be allowed to carry non-toxic products. That way everyone can afford a healthy home and we can return to thoughtless shopping. Until then, be eco and health conscious.
Here is a great site and a one stop shop to start getting the info you need to go green.