Houston's nightlife scene seems to be constantly on the move. Right now most of the action is centered in Midtown—between the Pierce Elevated and West Alabama on the north and south, respectively, and stretching from San Jacinto St. on the East to Brazos on the West. Healthy outposts can also be found downtown, in Montrose, and along Washington Avenue (streching from downtown to Memorial Park). There are popular places in the Uptown/Galleria area, too, but you'll find more international tourists and an older crowd than hard-partying twenty- and thirtysomethings.
The great thing about Midtown is that once you park you're within walking distance of all the area's hottest new places, as well as some old standbys. If you don't like crowds, loud drunks, or young people in general, this might not be the best place for you.
Houston's performing-arts scene is located downtown, and the city is one of the few in the United States with four resident performance companies (symphony, ballet, opera, and theatre). Shows are staged at Jones Hall, the Alley Theatre, and the Wortham Theatre Centre.
For complete listings of current events, check out the Houston Chronicle, Houston Press, and Where magazine.