Anywhere east of the airport, south of I70 and north of Washington is not somewhere you want to be. Soulard (between Busch stadium and the AB Brewery) isn't bad. Westport is a suburban wasteland, but good for a few bars. I stayed out in West County when I lived there and didn't have any crime troubles.

We had a good time at karaokie on Wednesday nights at Maryland Yards off Dorsett. I also spents lots of time at Growlers off Olive(there is a nicer one in South County, but that's far). They have 131 different beers. $2.50 drafts on Monday after 8 and discount bottles on Wednesday.

I was married when I was out there, so I don't know too much about where to pick up girls, but the scenery is nice in Clayton and the Central West End. Laclede's landing (where the Morgan Street Brewery is) has decent scenery too. If you want the best though, hit up the patio at McGurk's in Soulard. Best Guiness in town too.