Did a stag there last summer, had tons of fun!
Few 'travel tips'... drinks get more expensive the later the night goes, girls who lure you from a bar to the next one is a stripper, if you are in a pub full of ugly girls and there is one beuatiful girl - dont make a move on her - she is most likely owners girlfriend - and you get thrown out in an nice arch, and lastly, BBC reporters doing a TV report on stag parties in Riga don't have humor.
As I said, tons of fun!
Have a good one!