Not sure if your trip is over but here are some other choices. In walking distance, if you watch football, the Holiday Inn has a decent sports bar.
2-3 miles into Bound Brook you could check out Joes Meat Market which is one of the better deli's in central nj. All sorts of Italian foods, cookies, great sandwiches.
On Easton Ave, maybe 3/4 to 1 mile from your hotel is Lubbranos Pizza which was formerly Vinnies. The two that own it are really nice warm people and always take care of us, let us know whats good that day, whats freshest, etc. Might be worth the walk.
Then when your done, across the road is the Pie Factory. You can walk over and have dessert.
I think the restaurant scene is coming to somerset and a few are opening but thats a ways out.
I'm afraid you'll not find anything within walking distance. Your best bet, as mentioned by others, is to take a taxi into New Brunswick, where there are many excellent restaurants.
If you want to stay in Somerset, check out the following threads which pertain mainly to options in this small, mainly residential, community. There is some duplication and a couple of the restaurants already mentioned here are included. My favorite restaurant in town is Sophie's Bistro. I've never been disappointed at Sophie's.
As for O'Connor's, stay away. It has seen better days.
"Walking distance" means different things to different people, but the only restaurant that I would consider to be within walking distance is Jo Sho, the Japanese place that was previously mentioned. I would estimate that it is about 1/4 of a mile--or perhaps a bit further--from your hotel. Their food is good, although I have found their service to be less than good.
As others said, a cab ride into New Brunswick will open up a host of possibilities, and the previously mentioned New Brunswick restaurants (as well as Sophie's, which is in Somerset) are all good. O'Connors is a small step up from diner food, but if you are craving a burger, they do have excellent burgers, and their salad bar is better than average.
If you go to O'Connors, be on the lookout for the resident ghost! The building was built immediately after the Revolutionary War, and is said to host a female ghost who can be seen on the stairs leading to the upstairs "party room".
Jo Sho Restaurant..very good sushi, located close to where you are staying
Otherwise...head down Easton Ave to New Brunswick where you will find a great many places to done....here is a list, all of which you can google and find more detail...in no particular order:
Old Man Rafferty's good food, casual
Soho on George St
Stage Left (expensive, mixed reviews recently)
Daryl Wine Bar (small plates, great wines, one of my favorite)
Catherine Lombardi (Italian...some say good...many say overpriced)
Frog and the Peach (some really like)
In downtown Somerville is Verve (steaks), good food and wine
I have never been to this restaurant, but I have heard good things about it over the years from many. It may be the type of place you either love for nostalgic reasons and/or may hate because it is dated and uninspired. Never the less, it's only three miles from you accommodations and a short cab ride. I'll defer to others who are local or have experience.
These local legend type restaurants fascinate me. Myself, I am sure I could find something positive in a place that has been around for over three decades......even if it is for a pint of beer.
i've given that place 3 strikes and it is DEFINITELY out!
if you are truly looking for somerset restaurants without going to new brunswick i would say your best choice is on route 27 southbound called Luca's. it's in a strip mall, but once inside you would never know. i think the food there is above averages and they feature an extensive menu along with nightly specials. It is a BYOB but there is a liquor store by your hotel in the cedar grove shopping center that has relatively nice selections
csh- I worked in Somerset about 8 years ago and lived in New Brunswick which is the next town over. I don't recall Somerset having any restaurants within walking distance, unless you are next to the Marriott that faces Rt. 287. That being said, it's been a while since I have even been there but I suggest you try and arrange a taxi to neighboring New Brunswick, there are so many good restaurants there, some pricey but some great values. See what has been posted here on chowhound about New Brunswick and you will definitely find something good.