Hoya chinghungensis has been very good to me over the five years that I have had it.  I started out with a very small cutting from Aleagarden in Thailand and was able to grow it into this enormous plant that is covered with flowers for most of the summer.  I have also been able to sell at least 30 pots of it on Ebay over the past couple of years to help fund my little hobby.  I don’t think that you can ask more of a plant than that!