Here's the recipe I've used for years to much hoopla.

1 28oz canned tomatoes

1 bunch cilantro
1
med onion

2-3 cloves garlic

2-4 fresh jalapenos or serranos

squeeze of fresh lime juice

salt and pepper to taste

Combine all in a food processor and chop to your favorite consistency.
Food processors work better than blenders, they don't allow as much air
to be whipped into the mix.
BUT! Here's a new recipe I've just started using that I call my "cheater"
recipe. You won't believe how good this is after it sits for an hour or so.

1 14.5 oz can whole tomatoes

4 oz canned jalapenos

1 tsp garlic powder

salt and pepper to taste

I know what you're thinking but do you realize that your favorite Mexican
food haunt makes this or something very similar to this?
They can't afford
to make gallons of salsa from the previous recipe. You can also add the
Mexican flavored, chipotle flavored, or even "chili" recipe flavored tomatoes
if you're feeling guilty about it. I buy the "house" brand (cheap) whole
tomatoes. I promise you will love this and it costs about 60 cents per
16 oz serving.

Pico de Gallo
This is more of a "Mexican" salsa like you would see in old Mexico.
Goes great with fajitas and as an addition to "borracho"
beans.

3 ripe tomatoes or 6-7 Romas

1 onion

2-4 serranos

1/2 cup cilantro

juice of half lime

shot of fresh garlic (pressed)

Chop fine and combine

We also have an instant salsa that contains all of the above but tomatoes.
Combine our dry mix with 28 oz crushed or diced tomatoes.
(depending on the consistency you desire)