>>994949California's main fishing attractions in no particular order:
Mountain streams and lakes for fly and regular fishing, including brown, rainbow, brook, cutthroat, and golden trout (the real ones, not gold rainbows).
Multiple rivers in the northern half of the state that have runs of steelhead, chinook salmon, and coho salmon.
Offshore fishing for a wide variety of fish including salmon, halibut, rockfish, tuna, and yellowtail.
Many fishing piers in every part of the state that let you access good fishing water conveniently, with no license requirement, and learn Spanish at the same time.
Decent largemouth/spotted bass fishing due to the large number of reservoirs in the state which produce big fish as well as the delta.
White sturgeon, largest freshwater fish in North America, can be caught here.
A lot of interesting native fish for people into roughfishing/microfishing.
Alaska would be the best fishing state hands down if it wasn't so far away though.