No one's Italian cooking is better than Mom's or Grandmom's, especially if you come from an Italian family.
With that said, there are actually a couple really good Italian chain restaurants that are available nationwide.
Maggiano's would be the top of the list. Not only is their food out of this world, but if you go with 4 or more people you have the option of eating "family style." That means the four of you will split endless servings of 2 appetizers, 2 salads, 2 pasta dishes, 2 entrees (meat/fish dishes),2 desserts and any additionals that you'd like to pay for (such as side dishes or an extra pasta dish, etc.) I have tried (over the years) about 75% of the items on their menu and have yet to eat something that wasn't wonderfully delicious. The best items in my opinion are their 4-cheese ravioli, their Gnocchi in Vodka sauce, their Italian Pot Roast, their Beef Medalions. It's also the only place where I'll eat fried calamari.
Believe it or not, the Macaroni Grill is actually pretty good as well, especially since they're more along the lines of an Olive Garden sort of establishment. I think they're a level better than Carrabbas and leaps and bounds above anything you'll get from Olive Garden.
As for local places, there used to be some wonderful places in South Philly when I was growing up (such as the Royal Villa and Strolli's) but they are, alas, no more. Victor's Cafe (where you will be serenaded with opera music by the waiters/waitresses) is a local landmark (in the way that Palumbo's was before their fire).
There's another place in Philly, near 2nd and Cherry Streets called La Locanza del Ghiottoni. Not sure what it means, but I think it translates into "10 foot x 10 foot BYOB with pasta and chicken that are incredibly tasty." My Italian is rusty so that may not be accurate.
There's also Lombardi's (inside of the former Aladdin, now the Planet Hollywood Hotel/Casino) in Las Vegas. But my opinon may be skewed for obvious reasons.