I liked Wendy's a lot more before it was $16 for a combo meal (I know, same could be said about a lot of other fast food places now), but eh. SoCal's certainly not missing out because you don't have as many Wendy's as Ohio does. There must be at least a few of them in the area, as I remember stopping at one for breakfast a few years ago somewhere in the LA area, lord knows why.
There was a Wendy's right across the street from my high school, and there were MANY days of staying late for extra curriculars and eating there, and as a result, I probably never need to eat Wendy's ever again. A Frosty is good now and then, but even so, it's been years and I don't feel like I'm missing out.
I'm thrilled (and shocked, actually) that Culver's has made it that far west, but I don't know if I would go so far as to call them the best fast food restaurant. Their fries don't do a whole lot for me, and their frozen custard in my view is inferior to places like Freddy's or Andy's. They DO make a great burger, and I love their root beer, which is the ONLY root beer I seek out nowadays. I appreciate that they don't give out typical ketchup packets at the drive thru, but instead in containers that are actually conducive for dipping.
I like their product enough that they are my preferred burger joint if I'm on a road trip. Still, if given the choice, I prefer Portillo's.
In terms of underrated burger chains, I feel like Braum's has got to take the cake. They take vertical integration seriously and make everything at one farm in Oklahoma, and they refuse to build restaurants outside of a couple hundred mile radius as a result. Because they make everything in house and aren't beholden to suppliers, etc in the same way other restaurants are, their food is not only high quality, but cheaper than average. They also make delicious ice cream, which is not only high quality but also about the cheapest ice cream you can find now. If you haven't tried Braum's, you can certainly find them in the Dallas/Fort Worth area, or in Ozark, MO ~30 minutes away from Silver Dollar City, at the same exit as Lambert's.