What I want from salsa is good fresh flavor, a little bite, and for it to stick to a tortilla chip instead of forcing me to use one as a spoon. The way I get that is by using both cooked and fresh tomatoes, which is why I usually only make homemade salsa -- for chips and salsa, anyway -- in the summer.
This particular salsa takes half of the tomatoes, by volume, and dices them; the other half is roasted in the oven, peeled, pureed, and strained to get the seeds out. If you leave the skin on and proceed to puree and strain, you'll get a more noticeably roasted flavor -- I did that with some of the tomato puree I've frozen for the long tomato-less year.
While the tomatoes are roasting, the diced tomatoes are combined in a bowl with diced chiles (cherry bomb peppers and cayenne in this case), diced onion, a little garlic, a little Cuban oregano (it's more similar to Mexican oregano than Italian oregano, though it is a third plant altogether), and a little salt. That's it, you're done (though it will taste much better after a night in the fridge). Easy as pie. The puree, thickened by roasting, binds the fresh ingredients together and gives you chip-stick-ability.
Sometimes I add an acid like lemon or lime juice. I never add vinegar, though I know many people do. I think the combination of tomato puree, vinegar, and corn syrup in so many commercial salsas has a lot to do with why it's been outselling ketchup for almost twenty years -- it brings the products closer together. I want the thickness, but not ketchup-like qualities.
I add diced cucumber to salsa pretty often, but didn't in this case because it's a fairly large bowl of salsa, and if cucumbers sit in an acidic medium too long, they'll begin to pickle. I'll add cucumbers to this when I have little enough left that I know I'll use it up in a day or two. Also, the spicier your salsa, the better a combination the cucumbers will make.