Let's take 'Mambo Italiano' for what it's worth: a very enjoyable film stocked with a lot of laughs, but also poignant because there's no doubt that the tale has been pulled from the real life experiences of playright Steve Galluccio.
While leads Luke Kirby ('Angelo') and Peter Miller ('Nino') don't stand out in any way, it's Paul Sorvino and Ginette Reno as Angelo's parents who will stick with you. Yes, as others have noted, these are highly stereotypical portrayals. But it's Gaulluccio's life and *he* wrote the characters that way. Obviously, he's played it up a bit, but that gives Reno (and especially) Sorvino big meaty roles that they can really sink their teeth into. Watching Paul Sorvino is a treat. He's the kind of guy who could read the phone book to you with panache.
I also completely loved Mark Camacho's over-the-top, hilariously profane take as TV exec Johnny Christofaro. In a series of episodes that could again only have been drawn from playright Galluccio's real life experiences, the Christofaro character - in what can best to described as a series of 'friendly' profane explosions - rips into the writer, belittling his work, tearing down his confidence, but then finishing his tirade every time with an upbeat, sincere "How's your Mom?" Once Angelo hits the big time, there's Christofaro on an interview show in a classic exchange, remembering how he always encouraged Angelo to 'never give up' (replete with a series of now characteristic F bombs). Nothing could be further from the truth of course, which is what makes it so funny. Great writing.
A hidden gem: look for Galluccio appearing as 'himself' (in a way) - he's the 'TV version' of Angelo in the sitcom-within-the-movie.