If you've been watching the "Nightclubbing" series at the Siskel Film Center, you've seen rare early performances by Blondie, the Talking Heads, the Dead Boys, the Dead Kennedys, Suicide, the Go-Go's, Kid Creole and the Coconuts, and many more. If you haven't been watching these weekly screenings of early 1980s footage recorded at NYC clubs like CBGB's and the Danceteria, you've got one final chance this week, as the Film Center presents a greatest hits show, with directors Emily Armstrong and Pat Ivers showing up in person at one screening. See Slowdown for details.