19 worlds been shipped with The Sims 4 base game and expansion packs: Oasis Springs, Willow Creek, Newcrest, Granite Falls, Magnolia Promenade, Windenburg, San Myshuno, Forgotten Hollow, Brindleton Bay, Selvadorada, Del Sol Valley, StrangerVille, Sulani, Glimmerbrook, Britechester, Evergreen Harbor, Batuu, Mt. Komorebi, Henford-on-Bagley.
List of worlds / neighborhoods
Shipped with game: Sunset Valley, Twinbrook, Bridgeport, Appaloosa Plains, Starlight Shores, Moonlight Falls, Isla Paradiso; Sub-worlds: Shang Simla, Champs Les Sims, Al Simhara, Sims University, Oasis Landing.
Download-able: Riverview, Barnacle Bay, Hidden Springs, Lunar Lakes, Lucky Palms, Sunlit Tides, Monte Vista, Aurora Skies, Dragon Valley, Midnight Hollow, Roaring Heights.
Total: 23 worlds with 1845 lots and 499 families.
The Sims 2 base game come with 3 pre-made neighborhoods (Pleasantview, Strangetown, Veronaville), expansion packs add 11 pre-made neighborhoods: 3 normal neighborhoods (Riverblossom Hills, Desiderata Valley, Belladonna Cove), and 8 sub-neighborhoods which can be linked to each neighborhood separately and visited: 3 university campuses (La Fiesta Tech, Académie Le Tour, Downtown), 1 Downtown, 1 shopping district (Bluewater Village), 3 vacation destinations (Takemizu Village, Three Lakes, Twikkii Island).
Total 14 pre-made neighborhoods with 350 lots Additional 5 hidden neighborhoods do exist in game files and are used to generate NPC, they cannot be played.
I compiled in Excel a table with all lots from every neighborhood of The Sims 1: Neighborhood 1, Neightborhood 2, Downtown, Vacation Island, Old Town, Studio Town, Magic Town. Total 7 neighborhoods and 88 lots. Lot size, price, house / family name.