Jason
Los Angeles
I'm in Zurich this week for business and will have my evenings largely to myself (and possibly a few coworkers). What great bars, restaurants and nighttime adventures await me?
Budget's not much of a concern, but super-upscale might not be the level of fun we're after.
I'm staying by Hürlimann Areal and will be getting around on public transport.
As it is already summer in Zurich and because you are close to the area anyways you should definitely got to the lake and enjoy the atmosphere there (There are lots of little bars like Seebad Enge, but not sure if there are open already).
There are some neat little venues and bars around the Sihl, like El Lokal (website) or Stall 6 (website).
A very lively area with lots of bars is "Kreis 4"/ Langstrasse; a bigger venue there would be Volkshaus (website), good bars are Longstreet Bar (website), Dante (website), and Olé Olé Bar.
Another nice area - especially if the weather is summer-like as it has been in the last weeks (might be colder this week though) is the area around Hardbrücke (you can get there by train or streetcar from Bahnhof Enge); there is a great outdoor areal, Frau Gerolds Garten (website). It's close to the Viadukt (lots of small little artsy shops as well as the famous Freitag Flagship Store (website) store).
So these are just a few hints - there is lots going on in Zurich, hope that helped a bit already?
Enjoy and have fun!!
Mentioned in this answer:
JR
Debbie
Brew
Jason
Bianca
Keith
Andreas
Jillian
Ramon