I have a salsa recipe that gets rave reviews every time I make it! Unfortunately, I do it all "to taste" and until I like the way it looks, so I don't have any exact measurements for you. But it's definitely worth trying!
Start with ~6 or 7 Roma (plum) tomatoes, cut into largish chunks
Add a can of black beans, rinsed and drained.
Add a can of corn, rinsed and drained. I buy the kind that says it's "summer crisp," so they're not too mushy.
Add some chopped cilantro and chopped red onions. (I keep everything pretty "chunky," but I cut the onions a bit smaller.)
Add a clove or two of minced garlic.
Add chunks of either mango (I use the "Sunfresh" jarred kind -- always ripe, and YUM!) or peaches.
Add a few squeezes of lime juice and a splash of balsamic vinegar.
Add salt and pepper to taste.
Sometimes I end up adding a couple more tomatoes or maybe some more mango or peach, if I don't like the "color balance" I end up with. It's best to make this ahead and then refrigerate for a while. This allows all the flavors to mix, and allows the tomatoes to generate some juice. When you first make it, it will seem kind of "dry," but it will become more liquid-y after a while.
I love serving this with those lime-flavored tortilla chips!