We arrive BKK Friday midnight and leave early Monday. This is our first trip. Should we pre-arrange tours or just go to the market and wing it? Staying at the Shangri-la. Any feedback on river cruises either with the hotel or independent? Also restaurant recommendations in the area would be appreciated.
Thanks!

Not a lot of time Patricia but with just 2 full days I would recommend 1 day with a car and driver(guide) and see the Grand Palace and the major Wats etc. The next day perhaps on your own at the weekend market(JJ market) early in the morning to avoid the heat and perhaps the afternoon on a Klong tour either around your hotel or further up North on the river at Ko Kret.

http://wikitravel.org/en/Ko_Kret

I am a local so my perception of what to see in the city might be different from the viewpoint of a tourist. I am sure the other regulars here will chime in soon.

wing it when you get there i guess

My suggestions would be on Sat same as Hanuman said and on Sunday either to JJ as Hanuman said or go to Jim Thompson's house (I think it is open on Sunday) then after Jim Thompsons cross road to shopping in MBK, Siam Paragon and Siam Square OR after Jim Thompsons house go on river cruise.

So much to do, so little time. Depends on what you like.

Hi, thanks for your replies. We are on our way to Bhutan so just had time for a brief visit. Would just like to get a feel for the city and plan a real visit for another time. Would love a river cruise but without a buffet meal, any ideas?

Local travel agencies can provide tours. There are many travel agencies in just about every area that tourists stay in. On Saturday morning you could book a dinner cruise or evening tour or a day long tour for Sunday. Tour company will pick you up at your hotel. Doesn't hurt to check a travel agency out and see if something they have interests you. MBK has late hours. Chatuchak best visited during the morning hours.

I'd suggest rather than a river cruise, ride the water taxis. I consider it a quintessential Bangkok experience. It's cheap (go on the regular public boat rather than the tourist boat) and fun. I use the water taxis for transport whenever I can in Bangkok. Since you are staying at the Shangri-La this will be easy.

take a ride on a couple of the hotel boats for free from taskin pier

I agree with several of the suggestions. A market is definitely worth a half day with maybe a relaxed visit to Jim Thompson's house afterward. I also suggest a private boat tour of the klongs that you will be able to book at your hotel. Then, just for fun, do ride up and down the Chao Phraya on the express boats, like buses on the water. You can get off whenever the mood strikes you and it's wonderfully cool on the water. River City is one stop at an upscale shopping center that specializes in antiques. Fun to look if not to buy.