Sunset Valley is the only neighborhood shipped with The Sims 3 - the other one downloadable upon registration of a genuine copy. It is very large compared to the neighborhoods in previous The Sims games, having a total of 97 lots with various playable characters. There are lots of different types of houses like, a rustic home on a hill, a modern house in the suburbs, a house by the beach and many more. The main part of the town is the park, where you can have a picnic, go fishing or take a stroll and maybe meet someone new, there are also cinemas, gyms, restaurants, shops, pools, and other recreational facilities. Tons of places to work, where Sims can live out their dreams or crash and burn. Sims can now visit all their friend's and neighbor's homes and call up their friends with the new cell phone, and go out on the town and party. Sims also now can have a laptop.

Sunset Valley is not part of Simcity because Sunset Valley has all of its own services.

There are 21 available empty lots for you to build on. They are priced from $1200 at the cheapest, to $14,700 as the most expensive. The amount of space (in squares) for building goes from 19x29 at the smallest to 60x60 at the largest. The most expensive lot, 15 Summer Hill Court, is on the same hill and offers the same stunning vistas as the Alto estate.

When you start the game this is the Sunset Valley Story: "Before Pleasantview, there was Sunset Valley, founded by the Goths and built up by the Landgraabs to be a quiet, peaceful town. But when the Altos arrive with uptown ideals, will the townsfolk feel the need to choose sides?"

Sunset Valley is Pleasantview before the original in The Sims, which the neighborhood is named Old Town. The Goth Family are there as their younger selves, Mortimer as a child with his parents, as well as a few other familiar families, including the Bachelor Family.

New Families

The Alto Family - Simply described as "Nouveau Riche and Evil." Their family name may be a pun on the television series "The Sopranos." They seem to have a rivalry with the Landgraab Family. Their teenage daughter is Holly Alto.

The Andrews Family - Consists of married couple, Beau Andrews and Victoria Andrews.

The Bunch Family - Here's the story: Two working parents juggle family, household chores, and their careers while their four children run wild. What is the right balance for this family of six to stay sane?

The Clavell Family - Xander Clavell is an party animal still living in his parents' house. Buster is tired of Xander's mooching, and wants him out. Will Bessie have to choose between her son, and her husband?

The Frio Brothers - The Frio brothers may have a nice house, but they have personality issues which make them less than ideal as boyfriend material. Will Jared face the challenge of fatherhood?

The Hart Family - Father, Mother, and teen daughter. Sound boring? Hardly! Both parents have the Insane trait! Bebe is just trying to be a normal teenage girl, but how can she when her dad is wearing bunny slippers to her family's picnic and her mom is swatting imaginary pixies in the air?! Consists of Gus Hart, Dorie Hart, and Bebe Hart.

The Jolina Family - Jamie Jolina is an intelligent as she is beautiful. Can she prove to the world that two traits can coexist?

The Keaton Family - Try to keep up the sporty Keatons. Mrs. Keaton is a police officer and her husband works as a toddler sports coach in the Athletic Carrer.

The Koffi Family - Gobias Koffi is a well-meaning single sim who just hasn't met the right women. Is this because he actually prefers the company of his male friends?

The Roomies Household - Five young adult Sims with different and unique personalities living together.

The Ursine Family - Claire Ursine is a single lady who lives alone and loves to fish. She might seem like a normal woman, but it turns out she's pregnant (the father is Jared Frio) and she has a job in the Criminal Career!

The Wolff Family - A newly married couple living along the beach. It seems like they have the perfect life, but it turns out they rushed into their marriage to quickly before finding out that Thornton Wolff is against fatherhood, while Morgana Wolff wants to have as many children as possible.

The Single Moms Family - Fiona McIrish is used to living alone with her teenage daughter, River. But when Fiona's best friend needed a place to live with her own daughter, Fiona readily invited the two to live in her home. Will Molly be the perfect housemate or Fiona's biggest regret?

Families in the Family Bin

The Baker Family - Svetlana and Heathcliff love their daughter Becky, so of course they took her in when she and her son Topher needed a place to stay. But will they be able to enjoy their retirement with a noisy toddler in the house?

The Funke Family - Some might say that Sabrina and Rhett Funke are too flaky to be successful at raising kids. Will their three talented tots turn out ok in the end, or will they let the pressure get to them?

The Glover Family - Roommates Gwen and Holden are an odd pair: she's artsy and outgoing; he's spacey and bookish. Will they be just good friends, or something more?

The Lum Family - A family of three, with the teen son Lawrence needing to choose whether to follow his father Theodore or mother Lily's footsteps.

The Martinez Family - Lovebirds Pablo and Jennifer Martinez are outdoorsy folk looking to explore nature. Will they thrive in a new town, or will the suburban lifestyle eventually drive them to tears?

The Williams Family - Aimee Williams is a marvel in the kitchen, but her husband Marley is a bit of a dreamer. Will he be able to support the two of them and little Malika, or will Aimee have to use her skills to earn some dough?

Returning families
Families returning from the Sims 1 & Sims 2 nearly 50 years earlier are:

The Bachelor Family - Jocasta Bachelor and Simis Bachelor are raising their children Michael and Bella.

The Crumplebottom Family - Agnes Crumplebottom as her younger self, and her dead husband Erik Darling

The Goth Family - The Goth Family are the founders of Sunset Valley and are very wealthy. Since this is before The Sims 2, Gunther Goth and his wife Cornelia are adults, with Mortimer Goth as a child. (Mortimer Goth seems to have a crush on Bella.)

The Landgraab Family - Live the good life with the Landgraabs as long as your name isn't name Alto. The family consists of Geoffrey Landgraab, Nancy Landgraab, and their child son Malcolm Landgraab.

The Langerak Family - Kaylynn Langerak is a playable child Sim. She comes from a wealthy family which consists of Dustin Langerak, Iliana Langerak, Iliana's sister Zelda Mae, and their children Parker Langerak and Kaylynn Langerak.

The Pleasants, Burbs and other families from Sims 1 and 2 are not in the game, but it is possible to recreate them in Create-A-Sim.