Washington DC
Are you sure you don't mean Old Town Alexandria? I never liked Arlington that much, but Old Town Alexandria is a very fun place on the weekends and there are several hotels within walking distance of the Metro subway system into D.C. proper, like the Embassy Suites and the Holiay Inn and a few others both more upscale and less upscale.
There's a subway stop in Arlington, too, but...if I were visiting D.C., Arlington isn't the place I'd want to stay unless I had to. I'd stay in either Georgetown, Old Town Alexandria, or right in the middle of town at the Marriot Metro Center which has an awesome location at relatively inexpensive rates compared to other hotels in the same area. But if you've got money to burn, the other hotels in the center of town are great too.
It just kind of depends on what you're looking for. Arlington is pretty much the same as any other central suburb--the nightlife is just like you'd find anywhere else.
Old Town Alexandria is much the same, but its buildings are older and its bars get slightly more raucous and fun if that's your thing, plus it has some great sights and waterfront views and it's nice to be one of the many people who walk up and down its streets on weekend nights looking into nice shops and bars and the like. Many nice restaurants, too--everything from a "California-style" pizzeria to a wonderful slightly formal Scottish restaurant, right down King Street. How many other places actually have a Scottish restaurant??? Haggis, anyone!
The center of town or Georgetown near Adams-Morgan is really where you want to be if you like more intense nightlife. Lots of clubs, bars, anything and everything if you know where to look. Grab a copy of the free City Paper when you get to town (you can usually find it outside many subway stations, in some bookstores, etc.), and it will have ads for some of the major clubs and bars that should give you a general idea of their atmosphere. If you like strip clubs, I'd suggest either The Royal Palace near Dupont Circle if you like medium-to-good-looking girls who dance really dirty, or Good Guys or JP's if you like great-looking girls who look artificial and dance more inhibited.
As for whom to see, I don't know which "foreign language" you're referring to, Greek or French. If Greek, I can't help you with any firsthand knowledge. If you want incredible French in a very slender package, look at my review of Eve; but she's only available inall in Georgetwon or Rockville, and only on the days mentioned on the calendar at http://www.toris-secret.com/homepage.htm which is updated each weekend to show the next week's schedule. Any of Tori's other girls are also great choices. Appointments with any of Tori's girls can *only* be made, in advance, through the form on that website under the link "Make App't". It's generally regarded as one of the most highly rated agencies in D.C., the others being AHDC and MKCH.
Hope I was somewhat helpful. 