Belgian beer labels are a linguist's dream come true. The below six beers use Dutch/Flemish, French, Latin, and Marols. The back labels tend to list everything in Dutch, French, and German. On top of that, the names and designs reflect the abbey brewing tradition, with lots of dark religious themes that at times seem better suited to heavy metal album covers.
I don't have prices on these, although none of them are particularly rare. Think $2.50-$5.00 per 330mL (11.2 oz.) bottle, but most of these are also available in 750mL bottles, or will be cheaper if purchased by the case. Your best bet for trying these is probably at a bar that specializes in having a huge beer list, like The Flying Saucer. You might even be able to find some of them in draft form.
I served all of these in a brandy snifter, but if you want to be truly authentic, the various breweries produce specific shapes of glasses that bear the logo of the beer and are designed to most precisely deliver the aromas and flavors of that particular product. A serious beer establishment will have these, but they're really impractical for home use unless you stick to just one or two brands.
5% abv., Czech Pilsener
This comes in a small 250mL bottle (8.5 oz.). Light, crisp, and clean, and with the small serving size this is a good candidate if you plan to try several beers in an evening. It's named after the famous Brussels statue of a boy peeing in a fountain, Manneken Pis. Sometimes a keg of beer is hooked up to the statue and beer flows straight from the, er, tap.
6.5% abv., Belgian Dark Ale
Coffee and chocolate, a little bitter edge. Dark, with nice toasty malts, and a surprisingly crisp finish. If you like Newcastle Brown, this is a good second step on your way to enjoying darker beers. The original brewery was destroyed in 1794 during the French Revolution, but the modern facility is owned by the massive Anheuser-Busch InBev conglomerate, which produces 25% of the beer consumed in the entire world.
Grimbergen Optimo Bruno
10% abv., Belgian Strong Dark Ale
The strongest of our sextet, this one is rich and savory, with almost a soy sauce component. Pleasantly beery aroma without a lot of outside elements. While it's not thick or sweet, it does seem to coat your mouth and hang on your teeth for a while. Grimbergen is an abbey in the Dutch part of Belgium, and Optimo Bruno is Latin for "Best Brown". Odd combination, but they've been brewing there since 1128, so they can do whatever they want.
8.5% abv., Belgian Strong Pale Ale
Bitter, touch of herbs and grass, great hops. Recommended for fans of good bitter beers like India Pale Ales. It's really fun to serve a bitter beer like this as a contrast to something like pork with a sweet glaze on it.
8.5% abv., Belgian Strong Pale Ale
Light and crisp, touch of acidity, lots of bubbles. The name means "devil" in Dutch and was created to celebrate the end of WWI. The body of this beer is so light that the alcohol strength can sneak up on you, though out of all of the beers listed, this will probably be the easiest to find in supermarkets and bars.
8,5% abv., Belgian Strong Dark Ale
Dark and rich, full-bodied and strong. There's a touch of spice, and ultimately it's just delicious. Latin for night terror, also a play on the sister beer called Delirium Tremens, named after withdrawal symptoms. The bottle throws a lot of people off--it looks like a bottled milkshake, and has a pink elephant on it. But it's just painted glass, and despite the silly design, it is a serious beer. Definitely one to sit back and enjoy slowly after dinner.
P.S. Because I've been getting a lot of e-mails recently asking where to find things, these beers present a curious problem. Since the alcohol content can get as high as 12%, in various jurisdictions of the United States there may be no legal way to purchase them. Sure, you could buy a 12% wine, or some sort of watered down 12% liquor, but in some places anything above a certain limit (5% or so) isn't legally beer, but isn't able to be sold under another category. In other cases, you might be able to purchase the beer at a liquor store but not at a bar, or vice versa. Likewise, the way that these beers are classified and taxed will result in some big differences in price throughout the country.