A great new italian option in Palos Park is Francesca's Vicinato, the latest from the owners of Mia Francesca and Francesca's on Taylor. It's the best italian around. For a more homestyle approach to Italian, Devono's on 143rd and Wolf is a good standby. Very homey atmosphere...sometimes kitchen is a bit too laid back.
For Mexican, I like Burrito Jalisco which has been a mainstay for the last 10 years or so. It's on 159th just east of 94th AVenue across from Ricobenes.
Ricobene's is great for the their famous breaded steak sandwich - don't forget to get extra mozzarella and giardinera!
For CHinese, I like to head up 83 to Lao Szechuan in Westmont, but Hong Min on 111th in Palos Heights is very good as well.
Another great option on 111th ST is Taqueria Atotonilco which is just east of Harlem. They have the best al pastor meat south of 26th ST along with great standard tacos and tortas.
On Harlem just north of 111th is Al Ameer a delightful and friendly palestinian restaurant. Excellent hummus, schwerma and specials. I've never had anything there I didn't like.
For Burgers you really can't beat Top-Notch on 159th and Harlem.
There's two greek restaurants in the area - first is Dionysious which is on Harlem and SW Highway. Very good food, and average prices. Any stewed lamb dish is usually a good bet! The other greek place is the Grecian Corner on 111th ST a mile or so east of Harlem. This place is a little more rough around the edges than Dionysious but has some stellar dishes. They make their own yogurt - paired with honey this is an excellent dessert.
Anyway if you look around and avoid the corporate food there is some good eating to be had in the SW burbs...just have to poke around!