Many folks love to can their own tomatoes for use in the winter months when they can't find a tomato in the grocer to their liking. I personally put up only 50 jars or so. I know some folks do a hundred or more.
But I like to vary the spice and dried herbs in my canned tomatoes. The fun thing about spices is that you can add them to tomatoes without increasing the processing times for the water bath or the pressure canner, whichever you like to use.
For Italian tomatoes, I add basil, oregano, rosemary, thyme, garlic, and salt to my tomato base. In the winter, this combination makes wonderful base for a spaghetti sauce.
Rotel is one of the most recognized names in manufactured canned tomatoes. You can make your tomatoes sing with flavor like Rotel's, too. Simply add spices to your tomatoes when you are heating them to can.
For Mexican tomatoes, try chili powder, cumin, garlic, cayenne pepper, onion flakes, and coriander. You can even add some diced small chilis. If it's easier, open a can of chopped chilis and add them to your tomatoes. It won't change the processing time of your canner. I use Mexican tomatoes to make chili, enchiladas, and tacos in the winter - yummmm!