where is the best place to stay in bangkok for shopping, restaurants, nightlife etc?

I think you can do pretty good on Sukhumvit Road, lower number end. In this area you can use the Skytrain (Nana Skytrain stop) to get to many places in Bangkok.

From this Sukhumvit Road area you can walk to malls, restaurants, bars, travel agents and lots of street vendors.

Many hotels in this area in all price ranges.

http://www.travelfish.org/map_detail/thailand/bangkok_and_surrounds/bangkok/sukhumvit_soi_1_to_asok/8

http://www.thaifocus.com/bangkok/skytrainmap.htm

Good luck.

It depends on your budget, what type of accommodation / nightlife you are looking for and the type of food you like to eat.

Everyone will have there own opinion.
Personally I would go with the Sukhumvit area. Its a good area with lots to do, reasonably priced, nice hotels, close to alot of nightlife and the difference in price between this area and say the budget option in Khao San, is only about $10 more.

I have stayed in Khao San and Sukhumvit and would only go back to KS if I was low on cash or travelling for a long time and looking to economise. Khao San is the backpacker budget option so it is great if you are looking to meet up with other backpackers or travel buddies.

A great web site where you can get most of the info you need on areas, hotels, nightlife etc... www.bangkok.com

You will have a better idea of what would suit you best and most of the options are there.

Look for places along Sukhumvit Road and its vicinity. This is where you get access to what you are looking for.

Should be on Sukumvit, Rama 4th and Rachadapisek roads as there are SkyTrain and Subway accesses that you can take and run around in the city even at late night. Along these three roads, there are many many hotels in different classes and price ranges you can choose to fit your budget.

Obtain Bangkok map that includes SkyTrain and Subway routes and stations will help you lacate where you should stay easier.

Have a great time in Bangkok

i love staying in pratunam area and petchburi because i can use the sky walk to all the malls and places i want and its near all the markets, shops, restaurants
like try
Pratunam area
1)Baiyoke sky hotel
http://asiatravel.com/thailand/baiyokesky/index.html
just down of this hotel there are 2 small malls nice place and pratunam market

2)Grand Diamond hotel its near platinum mall and panthip when i stayed here i used to change go down and enter the mall its like 5 floors and they have cheap price clothes and shoes there is some coffee shops nice place
http://asiatravel.com/thailand/granddiamond/index.html

this is in petchburi area
3)ramada DMA hotel
http://asiatravel.com/dma_pavilion/index.html

4)Eastin hotel
http://asiatravel.com/thailand/prepaidhotels/bangkok/empress/index.html
but i like the hotels in pratunam area because the malls like world trade plaza, MBK, siam paragon, siam city mall, gaysorn, erawan are all connected together by a sky walk and you dont ned a taxi at all you can walk to there

6 Words ,All Night Plaza In Chiang-Mai! I am Thai and live here in Thailand .

For shopping in Pecthburi Road and for nightlife in Sukhumvit ( Soi Nana and Soi Cowboy) or Silom (Patpong)

For shopping, Pratunam.
For night life, patpong and sukumvit area

check this website.... got every hotels information in Bangkok.. one of them must right to your request...