At Friday night, if you are in a pub for celebrating something good, then someones do congratulate you. After that, you want to buy them drinkings in next round. What would you like to say?

For I, I'd say: 謝謝! 下一輪是我的! 乾杯!  when I met Chinese people a lot! However, if I met foreign people more: I'd say: Thanks all! Next round, on me! Cheers!