IMO Bear and Snow Summit are the best in so cal. Mt High is ok (I only go there cause its closer to LA for day trips). However, growing up on the east coast, all of the so cal resorts remind me of east coast hills. Typically icy man-made hardpack that softens during the day.
Bear is great if you're into park, and pretty good for cruising some groomers too (likewise for Snow Summit). Mt High has less park features, gets really crowded, and isn't able to make as much snow as Bear / SS. Plus these two are going to be way closer to San Diego.
Some natural snow places also exist but are much smaller in Mt Baldy and Mt Waterman (only open on weekends) near LA.
If you can make trips to Mammoth, I highly recommend it. Vastly bigger resort than anything in so cal, world class parks, and great snow conditions. If you're into backcountry riding there's a ton in the Eastern Sierra. I have no idea how long a trip from San Diego would be tho- maybe 8 hrs?
