Tokyo has one of the world's most active night scenes, and the range is huge. You can start the night with a salsa class, continue at a laid back reggae bar, and spend the last few hours in a monster club dancing to the top DJs in the world--and this is only the beginning.
If super clubs are your thing, you can't go wrong with Ageha. The main floor can hold 2,400 people, and there's two other dance floors, several bars and even a pool. The one drawback is that it is out of the way, but they provide a free shuttle from Shibuya all night long.
Womb was already famous before the movie "Babel" immortalized it around the world. It has been voted to the "The World's Top 10 Killer Clubs" several times, thanks to their impressive sound system. For hip-hop and the best MCs in Japan, head to Harlem in Shibuya. Since it opened in the mid-1990s, it has been one of the epicenters of hip hop culture. Club Atom in the same building has two floors playing R&B and hip hop as well. While in Shibuya, be sure to also check out Club Asia, which is extremely popular.
For a luxurious night that combines great food, lounge cocktails and dancing, head to Velours. Tokyo hipsters also rave about the lounges and sophisticated atmosphere at Le Baron de Paris, Air or Alife.
The foreign crowd has made some establishments, especially around Roppongi, their party favorites. Muse, Grace, Club Pure, and the cheap and somewhat raucous Gaspanic are among these. The crowds can be a problem at Gaspanic because they don't have an entrance fee; instead, you always have to be drinking, and the staff will come and check. The Latino bars are also popular. For salsa moves, head to El Cafe Latino or Salsa Sudada.
Finally, there are countless smaller clubs that cater to all tastes. You might want to try Loop, which specializes in house and techno, The Room, where the music varies between house and jazz, or Garam, where the Reggae beats will keep you happy. For gay & lesbian clubs, Arty Farty is Tokyo's de facto choice, though parties tend to rotate between clubs. Drop by the Advocates Cafe to find out what is happening.
Japanese clubs are a bit lax when it comes to checking IDs. It is always best to have one on you, but chances are you won't be checked (provided you're of legal age, which is 20). Most Japanese clubs also don't have a coat check, but offer lockers instead. Sometimes you'll get the money back, sometimes you won't. You'll also find that there are two clubbing crowds; one of them goes out early and leaves around midnight when the trains stop running, while the other shows up around midnight, and the party continues until dawn.