Right on the Buda side of the Petöfi bridge, this beloved club, restaurant, and bar, occupying a Ukrainian ship anchored in the Danube, attracts everyone from club kids (for the DJ shows) to couples in their mid-50s (for dinner and torch songs). On a given night, you might find France's ska-salsa sensation Sergent Garcia, England's electronic stars E-Z Rollers, or the Russian-English turntablist DJ Vadim. Unsurprisingly, the views over the river and embankments can't be beat; much more unexpected are the great jazz combos that add a relaxed vibe to what is ostensibly a party barge.

Open 11 p.m. to 4 a.m.

This spacious "train station" dance club pulses with a young, urban clientele, drawn in partly by the good tunes (mostly house and techno), partly by the funky atmosphere (created by the antique train compartments installed here), and partly by one another. Fun, noisy, and extremely smoky, Bahnhof is behind the Nyugati train and metro station on Váci, but be careful: Though both are in Pest, this Váci is Váci út (the main road) to the north, not the cute, shopping-friendly side street Váci utca to the south. Don't worry—your taxi driver will almost certainly know the way.

Closed Monday through Wednesday.

Located to the north of the city on óbudai Island, a.k.a. Hajógyári sziget, this vast cavernous lounge and dance club with brick arches, billowing curtains, VIP booths, and two elevated catwalks serves up sophisticated trance and house from visiting international DJs, such as Liverpool's Mark Knight and Frankfurt's DJ Tarkan (as well as local resident DJs). The beau monde is certainly shooting for the moon here. Girls garb themselves in all the finery they can muster, but only twice a week: Dokk is open on weekends only, though the hedonistic after-parties, which last until well after dawn, more than make up for the limited hours.

Open 10 p.m. to 5 a.m. Closed Sunday to Thursday. Closed from June through August.

Inside the Four Seasons Gresham Palace hotel, this swanky cocktail lounge brings international luxe and concomitant prices to Roosevelt Square, on the Pest side of the lovely Chain Bridge (Széchenyi lánchíd). Filled with an international, multilingual mix of hotel guests, well-to-do locals, and expatriate businessmen, the marble-clad space is somewhat dark, with a touch of intrigue. It's also expensive, and worth it, for top-shelf bottles served by well-trained mixologists at a marble-and-mirror bar beneath an arched skylight with Art Deco arabesques.

Open from dusk till dawn, this red-velvet underground lounge and after-hours club babysits a diverse crowd of urban vampires—the comfortably unemployed, Central and Eastern European layabouts, and modern troubadours—all paying homage to the eponymous Gallic goddess of heartbreak. Pick your poison: There's smooth jazz at the piano bar upstairs, or obscure disco and '80s pop songs on the packed dance floor downstairs.

Open 10 p.m. to 6 a.m.

This earthy coffeehouse and bar is quiet enough by day. At night, it turns into a raucous watering hole for a demimonde of avant-gardists, bicycle messengers, and castaway expatriates from a dozen nations. On weekends, live music concerts, ranging from freak-folk to funk, can make the philosophical conversations and accents that much harder to comprehend. But the photography and art exhibits, which would be at home in New York's East Village, are always a good diversion.

Open weekdays from 9 a.m. to 1 a.m. and Saturdays from 2 p.m. to 2 a.m. Closed Sundays.