Grape tomatoes do retain some of their flavor, and can sometimes be enough to hold off tomato cravings in the middle of winter. They still don’t stand up to the really good ones, though.
previous discussion on this topic: Lacking the gene to enjoy fresh tomatoes? - Factual Questions - Straight Dope Message Board
AKA why QtM loves all forms of tomatoes except fresh, and yes, he’s tried fresh from the garden ones, too. Many times, many varieties.
For me, personally, the fresher the tomato, the worse it tastes. Fresh tomatoes and smaller varieties of tomatoes have a stronger tomatoey flavor that I dislike. I prefer to eat a more flavorless tomato (or like they do in Spain, mostly green tomato). It’s more about the texture in a salad or sandwich than the taste.
For tomatoe sauces, even the best chefs (and cookbooks) recommend using canned tomatoes unless you’ve got killer ones on hand, which a) is unlikely and b) I wouldn’t use for a sauce.
Just be sure to get Romano (or plum) tomatoes, optimally those from San Marzano, labeled “D.O.P.” (Italian Government recognition of the origin). Plum tomatoes are thicker, ie, less water.
The cans labeled simply “San Marzano,” which you see a lot of here (NYC), is the name of a U.S. company that cans tomatoes. They’re OK, but there oughtta be a law. I now don’t buy them on principle.
There are plenty of foods that change flavor when cooked. Carrots, sweet potatoes, and tomatoes are just three examples. Sweet potatoes raw taste like milky-sweet raw carrots to me, but they take on a really nasty flavor cooked. They say taste sensitivity changes as one gets older- a cooked sweet potato would make me want to puke when I was a kid, but now they’re not quite as nasty. Same with carrots. I can’t really think of a veggie or fruit that people eat raw that changes flavor for the better when cooked, to my taste.
To me, tomatoes definitely change flavor when cooked (all canned tomatoes are cooked) but they don’t change for the worse, like sweet potatoes do. They taste different, but not bad at all to me. I definitely understand how cooked tomatoes could taste better to some people.
Celery is one I dislike raw, but I wouldn’t cook a lot of things without it.
Grocery stores usually carry more than one kind of tomatoes. At least one kind will be suitable to be consumed raw (and probably a bit more expensive than the others). Just ask the store attendant.