American cuisine, contrarily to a popular belief, is actually very good, as long as you stay away from McDonald’s, Wendy’s, or Burger King.
If you are in Cambridge, you ABSOLUTELY must try the famous New England Clam Chowder (many recommend it at Legal Seafoods, a nice chain restaurant with a location also in Harvard Square, although a bit on the pricey side). Quite cheap and excellent lobster is served at Noname Cafe in Boston. For the best lobster roll (warm with butter) in the area, visit Neptune Oyster where lines can be up to 3 hours.
For traditional hamburgers, tourists are often directed to go to Mr Bartley’s, conveniently located near Harvard Square. Even though it definitely is worth to go there (even if just to admire nice decor with old posters), I strongly suggest trying burgers at O’Sullivan Pub , located nearby (actually, just across Shaw’s supermarket). Their burgers are larger and juicier, it is possible to grab a beer in a pub athmosphere, to say nothing of their superior French fries (not the regular McDonald’s-type they serve at MrBartley, but real chunks of fried, non-peeled potatoes).
Zoe’s is a popular choice for an American diner, with breakfast served all day, and Egg’s Benedict closely rivaling the ones at the Upstairs on the Square and at Grendel’s. Another must-try option for breakfast/brunch is Alden & Harlow as well as Café Luna. A bit more upscale and pricier is Henrietta’s Table, which beats everyone else in breakfast category though (reservations highly recommended).
If you want to go to a fancy, expensive and really exquisite restaurant, Craigie On Main stands out (it is near Central Square), and within walking distance of Harvard Square Bergamot is an interesting choice. Even closer is an excellent Shepard – I went there with my then girlfriend and now wife right after I proposed! For another great and a little bit more upscale diner, visit Gulia, one of the favourites of many in Cambridge.