I am slowly reaching the conclusion that the town I now live in would be perfect for a MU* - Santa Barbara. Technically, I would use the whole County of Santa Barbara. The county has about 500,000 people in it with the Santa Barbara city area (Santa Barbara, Goleta, Montecito, unincorporated urban areas in and around them) being around 150,000, Santa Maria city area (Santa Maria, Orcutt, Guadalupe) being 130,000, Lompoc sits around 42,000 and you have a scattering other towns and cities (Ventucopa has a population of 90 in the middle of nowhere). However, there is quite a diverse mix.
Montecito has Oprah, Prince Harry and Duchess Megan, Steve Martin, and a bunch of other celebrities and other rich people living there. It's a bunch of gated estates and a couple of small-town feeling "villages" with boutique shops. Santa Barbara is your older, slightly snooty city with beaches and wealthy people with trendy shops and an actual downtown (the former Google CEO bought a mansion in the south of the city for $40 million). Goleta has more of a middle and working class vibe with some definite 80's influences to the architecture. Then you have Isla Vista which is basically a town that became all student housing next to the UC Santa Barbara, so it has the usual college town party scene. Santa Maria is your somewhat wealthier working class city. Lompoc is your not-so-wealthy working class city. Guadalupe is your Spanish speaking working class city. Summerland has the feel of a former resort town that is now filled with retirees (and Kevin Costner). Carpinteria feels like a city on the cusp of booming as cannabis and health care industries move in.
Then there's Vandenburg Air Force base for your military storylines and alien invasions. Solvang is a Danish town in the middle of California with its unique architecture and shops. Surrounding it are Buellton, Los Olivos, and Santa Ynez and the Santa Barbara wine country with vineyards and ranches. The Los Padres National Forest covers most of the mountains (which had snow this weekend causing Camino Cielo road to be closed for snow and ice, so you can still get your snowy weather stories). The Channel Islands are right off shore which are nature preserve, but you could pretend Catalina Island off of LA is also up here and have your island resort town too if you want it.
Honestly, there's a lot of variety in the county. Today for my job I went from a middle class-ish home in Summerland near the beach to a gated villa in Montecito to driving past snow-topped mountains to get to a home of a Trump supporter with an old 70s Mustang, who I am kind of surprised didn't pull a shotgun on me and tell me to get off his land with a thick Texas accent.
So if you wanted to tell a story about your character hob-nobbing with celebrities and tech millionaires in a vacation home or at the Ritz Carlton, while someone else is playing a vampire preying on partying college kids about 6 miles away, while someone else is playing a cartel member in a car chase with police 30 miles away, driving next to the most recent SpaceX launch from Vandenburg, while ALL of that is happening in an area that honestly feels like a bunch of small towns instead of New York, Chicago, or LA, that is entirely possible here.
There's even a strip club in Santa Barbara - a Spearmint Rhino - and a casino on the Chumash reservation in Santa Ynez, so you can find your vices too.