Cut avocados in half and remove pit. Scoop out flesh of avocado and coarsely chop it. Place in a large bowl and slightly mash with a fork. I like mine on the chunky side. Add the diced onion, tomatoes, cilantro, and garlic and toss together with the avocados. If you like your guacamole on the spicy side add some diced jalapeno here.
Add the lime juice, salt, and pepper to taste.
Chill until serving. If not serving right away place saran wrap directly against the guacamole so that it does not oxidize and turn brown. Serve with tortilla chips.