I prefer Asiana to the Great Wall. There is also Bamboo which has good Chinese. I also like Bedford House of Beef. Sparta is a little "townie" diner type restaurant. Flatbread Pizza is the only pizza I enjoy in town (even though there are many others). And do not miss having ice cream at Bedford Farms.
Arlington, Lexington, and Waltham are all very reasonable distances and have LOTS of options. Burlington and Billerica each have a few good places as well. In fact my favorite breakfast spot is Bellybusters in Billerica.
The Pongol- Indian buffet
New Jang Su - Korean BBQ
Sichuan Gourmet- 'nough said
L'andana- Mistral in Burlington
Summer/Winter- from the Arrow folks, in the Burlington Marriot
Kushboo- serviceable Indian
Dabin- Ok Japanes/Korean
Zocala- fairly good Mexican- had a nice chile relleno there
as above Ginger, Dalya's, I'd go Asiana Bistro, BHOB, Flatbread, Bedford Farms
and Ken's next to Ginger has burgers, subs, and a pretty good breakfast option
Arlington's not to far off- search the board, a lot
but: Toroya's popular on the board for sushi, Punjab for indian, Katmandu spice,
I'm getting tired.
Sichuan Gourmet -- couldn't recommend it more. My colleagues and I will not go anywhere else for lunch when we leave the cafeteria.
I also enjoy New Jang Su and Toraya as mentioned above. Another option in Lexington is Denian's, a new place serving homemade steamed buns and bubble teas. They are still getting the kinks out of some of the items but my Taiwanese friends said it reminds them of home! Lastly I want to mention Neillio's in Lexington. I think they do catering but they are good for lunch, especially the turkey sandwiches.
Bedford House of Roast Beef has excellent -- you guessed it -- roast beef subs. Haven't been in awhile but Dalya's was good when I went. Luigi's is not (to me) destination dining but when I worked nearby I ate there a lot and it was fine -- I would certainly use it if it were a nabe. The Japanese restaurant across from the common (is that Ginger?) is indeed good. That's all I can think of in Bedford. Searching for Lexington and Arlington is a good suggestion. Also Burlington.
Yes, Ginger is across from the common. There's also Great Wall, which has a Chinese buffet. I haven't been in ages but remember a lot of Asians were dining there. For the benefit of the OP, it's Cafe Luigi, which is owned by the same group as the Jimmy's steak restaurants in Arlington, Saugus (and formerly Burlington Mall), and Grassfield's in Andover.
They will be a short ride from Waltham, which certainly has more than its share of restaurants. Ditto for Arlington.
re: three of us
I love Ginger Restaurant in Bedford. I have only been there for lunch though, but they have a good selection of sushi and Japanese noodle dishes. At this point, I'll have to own to being vegetarian so I've only tried the vegetarian makis, but my friends have sworn that the fish they use for sashimi is fresh and high quality. I've heard people at work mention Dalya's in Bedford as well, although I haven't been there. An Italian place called Luigi's seems to have loyal fans among people at my workplace too.
In Lexington, Dabin is the place I go to for Korean and Japanese and they serve a mean bibimbap. As with other Korean restaurants, some of their tables have grills for preparing Korean barbecue. There is an Indian restaurant close by called Khushboo, which my co-workers praise, but which left me underwhelmed (granted I've only eaten there once.) Also in the same general area is an Italian restaurant whose name I cannot remember at the moment (not Bertucci's), which has a fairly limited menu but whose tomato sauce I love.
I hope at least one of these suggestions work for your friends.