The concept of a disco, is is bit different in Thailand. When you arrive you will get asigned a TABLE (sometimes with seats) and a waiter. Thais make reservations for the disco like we do for a restaurant, they even choose their preferred table.
When Thais go out, most of them drink whisky. They buy it by the bottle (or bring their own bottle to the disco/club/bar). This might soundsstrange to us, but most bars makes no big profit on the spirits. They make the profit on the ice and he mixers :-). So... the waiter will stir your drinks all night and make sure your bottle of whisky does not get empty quickly but your ice and soda/coke will. Going out like that will be a lot cheaper than going out on beers or going out at home.
Depending on the location you will pay between 500 and 2500 THB for a bottle of whisky, sometimes mixers included. Otherwise count on 200-400 per set of ice and mixers. The good thing is that you do not have to finish the bottle. You can write your name on it, and they will keep it for a number of days/weeks depending on the venue. And the next time/day/night, you just ask your bottle back and the story with the mixers starts again. This is a very social way of going out as you will notice.
Watch out, if you go to the right places, you will get drinks from the Thai around you... A perfect time to make friends.
Thailand has some nice beers. My favourite is Singha beer, since this beer has a nice, full flavoured taste. You can drink it on the rocks, and still keep a good taste. Oh yes, in Thailand it is common to drink beer ice cold from the bottle or on the rocks. The temperatures outside make the beer go warm in no time and with some ice you can enjoy it anyway till the end. Sometimes beer is kept outside of the fridge, together with juices, coke and mineral water. If you drink your drinks on the rocks, it is chilled in seconds and it keeps the fridge free for food. You'll get used to it, don't worry about this. :-)
There is also Chang en Leo (they are the cheaper alternatives to Singha) and of course a number of foreign beers like Heineken, Stella Artois, Hoegaarden (sold at a higher price)... Thais tend to like Heineken, since it is “exotic”. For me, as a Belgian beer lover, in Thailand I stick to my Singha. Recently I tried Chang from draft and the have recrafted the beer. At 150THB for a 1 liter pitcher with some ice, the beer really is OK now.