Teasers I found was more for the gentlemen, as it invloves young bar girls getting up and strutting their stuff on the bars from time to time.
Unless your g/f is happy to look at just girls then fair enough.
Strangly enough, for a good bit of swinging action with visitors to amsterdam (for some reason especially americans) you may want to visit the Grasshopper. You can see this from Teasers front door, look straigh accross the canal.
Basement is a smoking area for purchases (no alcohol).
Go in side door to the main drinking bit, smoke if you want to, there are always people to meet and fun to be had.
I know we did and we were only planning to have a beer, but achived success on night one, then returned every night for 5 nights and only failed once, and that was because the people involved were not really our type and were mainly into the amsterdam smoking thing.
At the end of the day, if all else fails, you at least get a nice drink at reasonably fair prices for amsterdam.