You should read this
http://travel.nytimes.com/2007/05/06/travel/06hours.html

Istiklar street of course :)
also around Golden Horn, Galata bridge, Ortakoy…

Well, I agree with Cinamonas and Vonnegutnut. Istiklal Street, for one, is the most popular entertainment district in Istanbul. Try Ortakoy too if you want to see some good view of the city. But definitely try roof pubs in Istiklal, both the view and the parties ;)

Here’s what i’ve found out. But I think the main area that you guys should hang out at sounds like Beyoglu.
MOJO is a rock bar with a good band named Circus on Saturday nights.Its known to be too crowded on fridays and saturdays though.

Across the street from MOJO is HAYAL KAHVESI, highly recommended rock bar.

MIKLA is a Turkish-Scandinavian fusion restaurant on the top of marmara pera hotel.

Here’s a good website to about Istanbul’s nightlife

http://www.i-gunler.com/en/istanbul_night.php

then there’s a new nightclub for musiclovers with art school students’ works hanging off the walls called GHETTO the address is Kalyoncuk Kulluk Avenue No: 10 Taksim

babylon is also very recommended, find the details on their website http://www.babylon-ist.com/b2003/en/index.asp

close to babylon is a restaurant called TAVANARASI which means “attic”. They have good food.

there are some winehouses across the British Embassy called PANO and VICTOR LEVI are good ones.

CEZAYIR is a good restaurant. find more details at http://www.cezayir-istanbul.com/en.index.htm

Link below is for the classical experience of turkish drinking, raki of course and mezes, a very mediterranean way of enjoying food and company. For a listing of “meyhanes” check below
http://www.mymerhaba.com/en/main/content.asp_Q_id_E_920

Check Peyote in Taksim as well, where awesome bands play.

enjoy! :)

Flamme… I think that’s the right spelling. In the Galata area… lovely bar, and the chocolate lava cake is to die for. A bit pricey, but worth it.

And Eftalya, on the Galata side of the Galata Bridge – not ON the bridge, but overlooking the water. NOT pricey. You’ll see it, if you walk down near the cruise ships. I felt completely pampered there – it was chilly, and the manager brought us soft woolen wraps. I had blisters on my feet and was in a bad mood; they gave me Raki. Suddenly, I loved everyone on the planet and the blisters miraculously disappeared. ;)

Vonnegutnut and purplekedi know what they’re talking about. No need to repeat the same stuff over and over again.

Just a slight thing; what do you describe as fun?

A recklessly getting thrashed type of a fun (where you wake up the next day and don’t remember anything else but you had a lot of fun); overdo what vonnegut says about istiklal. Drink and dance and pub crawl!

But if your description for fun includes enjoying Istanbul (by the means of food and culture) and having pictures in which you are actually looking at the camera (or can look at the camera), than go for purple kedi’s advices.

Have a fun trip (by your descriptions of course)