Keep in mind some some rental companies charge a dropoff fee and some don't. We did our Cali trip last summer - I started with Hertz but ended up switching for various reasons.
I started looking seriously in March for a July trip (typically I find best prices for car rentals about 2 months out although occasionally I try much farther out and rebook if prices drop). Sometimes airport locations are cheaper, sometimes offsite is cheaper. All the places I looked in Cali, offsite was cheaper, even including cost of uber to pick up.
Reservation #1:
Booked: March 2015 for July 2015 trip
Hertz 1 week intermediate vehicle. pick up San Jose (offsite), drop off Anaheim. $314 incl all taxes and fees (watch for that - the car was only $282), AAA discount.
Reservation #2:
Booked: June 17 2015 for July 10 2015 pickup
Hertz 1 week intermediate vehicle, pick up Burbank (offsite), dropoff Anaheim. $249.85 incl all taxes and fees. AAA discount + $20 coupon from Hertz website
Reservation #3:
Booked: June 17 2015 for July 10 pickup
Avis 1 week convertible, pick up Burbank (offsite), dropoff Anaheim. $356.09 incl all taxes and fees. Maybe AAA discount? I forget. I also used a $30 off coupon from somewhere.
We went with the convertible
It was a blast - but I had to pack VERY little. We spent almost 2 weeks with just 2 carry-ons and a backpack for a family of 4 (2 teens). I did laundry twice and packed super light. Worth it though - the convertible was super fun in California!
Anyway, I originally booked our trip to fly into San Jose, travel down the coast and then cut across to Sequoia/Kings Canyon and then down to Anaheim. In June, we decided to add a day to our trip. I couldn't find decently priced flights to San Jose/San Francisco. Also, DH was dreading the winding twisty drive down the coast. So I switched things up at the last minute and flew to Burbank. We started by driving up to coast past Santa Barbara, stopping in San Luis Obispo and Pismo Beach (loved the tiny town!). Then across to Sequoia/Kings Canyon. Here we stayed one night in a tent cabin in Kings Canyon and the 2nd night in a motel room at Hume Lake. We LOVED SEKI. Those trees were incredibly majestic, we didn't have to deal with insane crowds, and it was just gorgeous. Did a bunch of hiking. My DH and DS really liked the summer camp atmosphere of Hume Lake - my son went paintballing, paddleboarding, etc.
We skipped Yosemite that trip. We finally decided the driving was too much for us. Especially since SEKI was on my must-do list. I have a few friends who have been to both, and they all said I would prefer SEKI. One day we'll get to Yosemite
I'm glad we chose SEKI. My son isn't too patient with lengthy road trips and even the 2-4 hours a day we did for the week before DLR was a lot for him and he was complaining a little.