Just few kilometres outside Bangkok but still far enough to not yet have been converted into a full scale tourist attraction is the charming Taling Chan Floating Market.
It has everything you need to spend a good half day without having to book a tour and it is far more genuine than the big famous markets.
Here you can enjoy a great seafood lunch sitting on the floor with the locals, ride a longtail boat around the nearby klongs (canals) for a 100 baht, do a bit of silly shopping and a lot of food tasting. You can even get a foot massage under the trees for only 200 baht! Enjoy it while it still feels 'local' as it already started to change.