I've read many a post regarding the food in the Pioneer Valley. A lot of it I disagree with, hence me making this post. As a preface, I'm a native Californian and have lived in Italy, thus I have a familiarity and love of Mexican and Italian food. Here's my take. PS, coffee means espresso and drinks built on espresso.
My overall feeling is that the area is saturated with mediocre establishments with elevated prices. Prices tend to be much higher than the quality warrants. It is difficult to find a place that delivers good value, which is a shame in a college-dominated area.
So first, I will talk about what the Valley does well. First is coffee and cafes and breakfast. At Amherst and Northampton Coffee (same owner), you can find first-rate espresso, the likes of which would make an Italian happy. Northampton Coffee is tucked away down Pleasant Street and thus you leave behind the hipster buzz that you find at other Northampton cafes. Amherst Coffee is a much quieter place than Rao's (for example), much easier to relax and/or get work done there. Esselon cafe in Hadley is another great place, they do an excellent breakfast (best eggs benedict in the valley) and have a beautiful outdoor area for fair-weather eating. I'm told it's good coffee there, but never had it. Black Sheep in Amherst is more of a bakery/deli than a cafe, but it makes great pastries, good sandwiches, and has a good atmosphere. That said, their coffee and tea leave something to be desired. Haymarket Cafe in Northampton makes a great breakfast, good lunch/dinner entrees, serves great tea and mediocre coffee. They also get major points for delivering good, interesting food at affordable prices. Unfortunately the hipster cool is in full effect there, but once you're done dealing with the "service" you can enjoy your meal and or tea. Of places that are more breakfast joint than cafe, Sylvester's makes a good eggs benedict, but the rest of the menu can be unimpressive and the staff can be brusque to rude. Jake's is simply and hearty, but nothing special. Both Sylvester's and Jake's are overpriced. Places I've found less impressive are Rao's (Amherst), Woodstar (Noho), and Lone Wolf (Amherst). Rao's serves awful coffee. Woodstar has unimpressive sandwiches. Lone Wolf has a bad eggs benedict, and bad Mexican breakfasts.
Of delis, Black Sheep takes the cake. Hayfields in Northampton makes delicious (sweet) muffins, and good sandwiches. Terrible coffee though. The Polish deli in Northampton makes a great reuben and decent pierogi. Unfortunately you can't get a good $5 sandwich anywhere. All of the above are going to set you back roughly $7 with tax.
Best coffee: Northampton Coffee
Best pastries: Black Sheep
Best eggs benedict: Esselon
Best sandwich: Black Sheep
Now onto international foods. Mexican: the Mexican food here sucks. There's no other way to put it. Any place that puts iceberg lettuce in your burrito and leaves out cilantro is not worth your dollar. Bueno y Sano is trash. It's incredibly bland (mm, black beans and iceberg) and well overpriced. Veracruzana is slightly better, at least they have cilantro (if you ask, they will substitute it for the iceberg that comes standard) and some interesting things like nopales and (real) chorizo. That said, they are way overpriced as well and their food also tends to be bland. Autentica (South Hadley) is anything but. Mi Tierra (Route 9, Hadley) is the saving grace for those who know what to expect from Mexican food. It serves properly spiced and flavorful food for reasonable prices. I've tried multiple dishes there and all were done well, in particular the spicy pork. It's too bad they don't serve carnitas. Mesa Verde up in Greenfield does OK Californian style Mexican, fish tacos and the like. Priced properly as well.
Best Mexican food: Mi Tierra
Asian food: almost as bad as the Mexican, overpriced and boring. The good places are Osaka, Soo Ra (both in Noho), Great Wall in Florence, Lhasa in Noho, Dynasty Gourmet in Easthampton, and the Korean joint in Hadley (everyone likes it, I haven't been yet). Osaka does good sushi , but it isn't likely to impress those used to the top flight places. Soo Ra does some good Korean, in particular their fried appetizers, but I have had a couple bland entrees there as well. Great Wall serves some interesting, tasty Chinese. Supposed to have excellent dim sum. I've been to Lhasa once, and really liked their dumplings. Dynasty serves your basic, everyday Chinese, but has excellent bang for the buck. Now onto the truly mediocre: Fresh Side, Amherst Chinese, Thai Garden, Siam Square. The former is bland. The latter two can't do noodle dishes well at all, and all I'm looking for is a good pad khee mao/drunken noodles. The red curry at Thai Garden is passable, but the curries at Siam Square are really boring. Last, and least, are the places which look so similar that I'm unlikely to try any of them: Teapot, Zen, Moshimoshi, and Taipei and Tokyo (all in Northampton). In short, you can find Asian food that will make a foodie happy, but nothing exceptional.
Italian food. Bad, but so it is everywhere other than the major East Coast urban centers. Pizza, no one does a real Italian pizza (or even a good approximation like Regina's in Boston), but for American pies Joe's and Luna in Northampton are excellent. The former is deliciously oldschool in atmosphere and food. The latter has great fresh ingredients, like their mozzarella, sausage, and mushrooms (whole button, not sliced). Pizza Paradiso is decent, but I prefer the above two. Antonio's and Pinocchio's are both mediocre to crappy in my opinion, regardless of what toppings they put on their pizzas. Mimmo's is like eating a big piece of cardboard. Sam's, a new place that just opened in Northampton, is a carbon copy of Antonio's but with better crust. We'll see how well they do.
Indian food. Paradise of India in Amherst is truly awful. I've heard the same of India Palace in Northampton (Main St). India House (Northampton, State St) is reputed to be good, but $15 for a lamb vindaloo? Please.
For burgers, Packard's is excellent but sometimes will overdo your burger. Amherst Brewing does an OK burger, but clearly comes in second.
For ice cream, Herrell's in Northampton takes the cake, but I'm a gelato lover and can't get overly enthusiastic about ice cream. That said, their hot fudge is delicious and they have some interesting flavors. Bart's in Amherst is mediocre.
For beer, Moan and Dove (S. Amherst) and Dirty Truth (Noho). Both stock interesting local and international beers. The latter has about 50 taps, the former has maybe 20. This area is truly blessed by these two bars and the abundance of local brewers.
Now for all the rest:
Amanouz (Moroccan) - terrific fish dishes and vegetables. Good portions sizes, reasonably priced.
Cafe Lebanon - bleh and way, way too pricey.
Chez Albert - good but not outstanding.
Judie's - an upscale Applebee's.
Spoleto - an expensive Olive Garden.
I've yet to try Circa; Blue Heron; Night Kitchen; Sierra, Eastside, or Apollo Grilles; Tavern on the Hill; but these places are on my list.