What are some things to do in Bangkok, Thailand?

I will be traveling to Bangkok for business in early May, and will be taking my wife with me. It is our first time there. We will have one weekend to ourselves, but other than those two days, my days will be taken up with work. What are some things that we can do or see together after my business day has ended? Any recommendations for the weekend? We would also like to know of some nice restaurants for while we are there.