Other hardcore types, go to Moshe Shem-Tov's Israeli Dance Marathon, an annual event that lasts until 3:30am.
Yes, you read that correctly.
Moshe is the pre-eminent "Markid" of Israeli Dance in the DC area and has a weekly session on Thursday nights (for all levels) at Tikvat Israel congregation in Rockville.
It's a great time for people at all levels (Moshe is a great teacher) and the crowd is very friendly.
Normally, I am at home while the nameless one is in attendance, but the young dancing proteges, the famed duo of Paco and Tonka made an appearance, much to the crowd's delight.
We saw some old friends, like Mike Fox, (love the branding) and made some new ones (like Aviva Albert, who brought her coloring book)