Well, you’ve got earlier, more “earthy” Fellini: I Vitelloni, La Strada or The Nights of Cabiria. Plus, of course, the incredible La Dolce Vita.
You’ve also got the works of Roberto Rossellini & Vittorio De Sica. Though I think the former is a better filmmaker, the latter tends to be more accessible and audience-friendly to the non-arthouse types. The Bicycle Thief is the one everyone knows, but Shoeshine is its equal (at least) and is on DVD. General Della Rovere is good, too, and The Gold of Naples is a lot of fun.
Generally speaking, I’d steer clear of Pasolini & Antonioni in this situation (though they’re both terrific in their own right). Some other directors you might try are Francesco Rosi (Salvatore Giuliano), Luchino Visconti (Ossessione or Rocco and His Brothers), and the Taviani Brothers (Night of the Shooting Stars).
Needless to say, most of the films I’ve listed are in B&W, if that’s an issue.
Also, Martin Scorsese made a wonderful film about his love of Italian Cinema called My Voyage to Italy. Not only are his observations interesting and personal, but he’s very generous in the clips he shows and the analysis he makes, so it’s a great source if you want to explore some classics but don’t know where to start.