In a large bowl, combine diced tomatoes, onion, jalapeño, cilantro, lime juice, and salt. Stir and let the salsa sit for 30 minutes for the best flavor. Stir again and serve with tortilla chips or with any Mexican meal.
Note-you can serve the salsa right away, but I think it is best after it sits for awhile and the flavors have time to meld. This pico de gallo is best the day it is made, but you can keep it in a container in the fridge and enjoy the next day.