Obviously setting aside DLR, for me Yosemite NP is number 1 by a fairly wide margin. Approaching from the south you come around the ridge at Valley View and it just takes your breathe away. Get’s me every time. Worth at least 3 nights, particularly in late June/July when the waterfalls are going full force. Stay IN the Valley.
Next would be Death Valley, an amazing and fascinating National Park. 200ft below sea level in places with snow capped mountains in the background, stark and beautiful at the same time. 2-3 nights here is always worthwhile but when it’s the best time for Yosemite (and my next recommendation) it is very hot in DV.
My next favourite is between the 2, Hwy 395. There are several wonderful places along this scenic Highway from the exit of Yosemite NP at Lee Vining (via Tioga Pass, Hwy 120 which is closed in the winter until late May to mid/late June) and Lone Pine on the way to Death Valley. Go slightly north of Lee Vining to see Bodie Ghost town then head south and visit June Lakes, Mammoth Lakes, Mono Lake, Lone Pine with its Movie History and the nearby Alabama Hills (where many films were shot) and Mt Whitney, the highest mountain in the continental USA. You could spend a week exploring this Hwy but a couple of nights between Yosemite and Death Valley makes for a great road trip.
Then I love LA. It’s so close to DLR but many never go apart for maybe a visit to Universal. There are so many things to see and do from Griffith Park and it’s many attractions (Observatory, Old LA Zoo, Hollywood Sign, Greek Theatre etc) to the La Brea Tarpits, Santa Monica, Original Farmers Markets, Koreatown, Olvera Street, California Science Centre, Petersen Automotive Museum, Getty Villa and Getty Center, Grand Central Market and Malibu to name a few.
From LA, a drive to San Francisco along Hwy 1 and 101 takes in the magnificent Big Sur, an amazing stretch of coastline between Ragged Point and Monterey. That short section will take you all day there is so much to stop and see. On the way there, Santa Barbara makes a great stop for 2-3 nights then there’s Pismo Beach, Morro Bay, Avila Beach, Cambria and Ragged Point. I’d recommend at least 2 stops, 1 before big Sur between Pismo Beach and Cambria and the other in Monterey, Carmel or Pacific Grove. If you do stop in Santa Barbara, make it 3 stops.
I also really like San Diego. It’s a great coastal city with the lovely Balboa Park, a massive recreation area incorporating the San Diego Zoo. Coronado, Old Town, Gaslamp District, Safari Park (just outside SD) and the Midway Museum are other Highlights.
A great loop roadtrip is LA (3-4n) to Santa Barbara (2n), Cambria/Ragged Point (1n), through Big Sur to Monterey (2-3n), Yosemite (absolute minimum of 3n), Mammoth Lakes (1-2n), Death Valley (1-2n), San Diego (2-3n) and back to LA or fly home from SD.
If that’s too long then LA (3-4n), somewhere between Pismo and Cambria (1n), Monterey (2n), Yosemite (3n), Mammoth Lakes (1n), DV (1-2n) and back to LA or on to Vegas and fly home from there.
There’s plenty more but those would be my top 5 favourite cities and areas in California and I’ve gone on long enough