Need a restaurant in the Lindenhurst area (more)->
Lindenhurst used to be a real good food town. Shroeder's is a legendary old German, really fun, on Wellwood Avenue, and that might be your best choice. There's a cheaper German (hard to burn $100, though) that's also good, a pretty good suburban chinese, and a few other odds and ends, but Shroeder's may be the best very local bet.
If you want to look wider, see any of the zillions of Long Island tips on this board. Hunam in Levittown might be a good choice...I love it dearly (see my previously described suggested orders...use the search engine)
La Parma in Huntington is a little north of there.
There is a new place on Rte.110 called Jillian's which is like a Planet Hollywood but with an arcade & bowling alley. There is a nice restaurant at Colonial Springs Golf Course called Alfred's which got a decent review in the NY Times.