Now: This section of Market Street, from about Taylor/6th Street to Van Ness, is seedy - there is no way to sugar it. Probably many a straying tourist has been scared back to Union Square, thinking this is what the "rest" of San Francisco is like. It can be a fascinating (daytime) walk, with many art deco furniture shops.
Then: It wasn't always random shouting and needles. Theatres were built here in the 1920s because it was a humming thoroughfare.
How To Get There: From the Powell Muni/BART station, walk west on Market Street and you're there. If your destination is the Orpheum Theatre, you can exit at the Civic Center station.

Golden Gate Theatre, on Taylor Street and Golden Gate Avenue, facing Market Street

Stores on Market Street near Jones Street

The Hibernia Bank Building, facing Market Street at Jones Street

Market Street at 7th Street

The Orpheum Theatre, on Market Street at 8th Street

Golden Gate Antiques on Market Street

Art Deco, on Market Street

Cav Wine Bar and Kitchen, on Market Street near Gough

Cafe Trieste on Market Street

Retrospect Furniture on Market Street

Antiquario Antiques on Market Street

Market Street Cinema, on Market Street at Jones Street

The Warfield Theatre, on Market Street near Taylor Street

Market Street at 6th Street

Farmer Brown - Southern Food, where Mason Street meets Market Street