I LOVE going to open markets in Vietnam. The fruit and vegetables are always fresher and cheaper than the "western" grocery store. Plus, I get to practice haggling with the vendors. I don't think I ever get a fair price, but I still get a kick out of it.
Unfortunately, I prefer to stay away now, because they can get a little crowded.
I wish I could get the hang of haggling. I have friends who swear it is the only way to do business in certain places around the world, but I have not mastered it!