At Exit 56, you will find good Italian at Cafe La Strada, just south of the Long Island Expressway, and fine new American at Venue 56, just north of the LIE. For Thai, try Thai Angel is the Islandia Shopping Center, just south of Exit 57 on Veteran's Memorial Hwy.
Thai Angel Restaurant
1812 Veterans Hwy, Islandia, NY 11749
Cafe La Strada
352 Wheeler Rd, Hauppauge, NY 11788
470 Wheeler Road, Hauppauge, NY 11788
San Marco, Sempre Vivolo are near my husband's job and he says they're decent. Kotobuki for Japanese. For more modest Italian or great pizza, Branchinelli's on rte 111 in Smithtown.
You're close enough that you'd be crazy not to visit Kitchen a Bistro in St. James; it's cash only, BYOB. Ate lunch there today, and it is my strongest recommendation in the area. Also, Maize Cantina in nearby Commack is getting a lot of excellent reccos on these boards. Very friendly and modest, great food, creative Mexican cooking, an imaginative chef at work. Try searching on these boards for nearby Smithtown, St. James, Commack.
1141 Jericho Tpke # 1, Commack, NY
Sempre Vivolo Restaurant
696 Motor Pkwy, Hauppauge, NY 11788
766 Route 25A, East Setauket, NY 11733
555 Route 111 Ste 2, Hauppauge, NY 11788
I heartily second Kotobuki for Japanese (especially the sushi). It was recommended by a front-desk employee at the Long Island Marriott as her favorite local recommendation, and it did not disappoint. The rock shrimp and fried oyster appetizers were nice, too.
Kotobuki Japanese Restrnt
377 Smithtown Byp, Hauppauge, NY 11788