There's gazpacho . . . and gazpacho. By that I mean that there are about as many kinds as there are people who make it. And the version with tomatoes is only one of many. To me, the "secret" is to keep it as simple as possible and use the best seasonal produce. And I like to leave it chunky.
When I get a craving for it before tomatoes are in season, I chop up mild onion and lots of garlic and puree them in the blender with tomato juice (or even better, the spicy version of V8; see, lentil, you're not alone ;) ). Then I mix that with finely chopped cucumber, bell peppers (any color), sherry vinegar, a little hot sauce such as Tabasco, and a good strong olive oil. Chill. Season with salt and pepper and adjust the spiciness just before serving. Sometimes I add a dollop of unflavored yogurt to each serving (this is especially good if I made it a little too spicy :blush: ). You could add croutons, but I don't usually.
When tomatoes are in, I seed a few, puree them with the onion and garlic, then seed and dice a few more to add with the cucumber and peppers etc.
A couple of weeks ago I had a version in which cantaloupe was substituted for the tomatoes, and chipotles were used for spiciness. That was great!
And then, of course, there is white gazpacho -- no tomato at all. Blanched almonds, crustless white bread (has to be really good, no Wonderbread!), garlic, and wine vinegar are pureed with ice water. The garnish is seedless green grapes (some prefer them peeled). (I also have a version that used roasted blanched hazelnuts.)
Another white gazpacho uses cucumbers, green bell peppers, bread, garlic, egg, oil, and wine vinegar, all pureed together, then strained, and the liquid thinned with ice water. More cucumber and green pepper for garnish. You could use a light chicken stock instead of the water.
"Notorious stickler" -- The New York Times, January 4, 2004