Suggestions for places to eat & hang out at wkends (Bangkok)

I am visiting Bangkok for a week for work - arrive Sat afternoon - and looking for suggestions on where to go on Saturday night and Sunday. Looking for somewhere to go for food and a couple of drinks - preferably somewhere outside where I can chill out and people watch. I was hoping there might be some internations activity over the weekend that I could join. Any suggestions would be great as it's been a very long time since I have been to Bangkok - I'm sure it has changed heaps since I was there in the 90s as a very poor backpacker staying in the Kao San Road!