Like many people here, I often rotate a few (they get SOOOO jealous if they're never carried!). My favorite is a custom Ryan Model 7. However, it's about a 4.3" blade and therefore risky to carry in LA.
When I'm in an area where law enforcement supervision is more probable, I like the Spyderco Delica, the smaller CRKT Crawford/Kasper, the Benchmade Mini-Stryker, the smaller Timberline Kelly Worden Tactical, and the medium CS El Lobo/Voyager. Of course, there are plenty of others around 3" and a lot depends upon how they fit your hand. In such situations I generally go with modest to moderately priced factory knives because if I have a knife confiscated, I don't want it to be an expensive custom.
Some of the foregoing knives are listed by the factories at 3" blades, which is technically a hair over the LA limit. In the first place, I think it is unlikely that you would be prosecuted for a 3" blade when 2.99" would be OK. However, it could conceivably happen and the response at that point is to argue how the blade is measured. In the knife law forum someone cited a California case in which the Court of Appeal ruled that you measure the sharpened cutting edge, not including the unsharpened choil/ricasso area. Many of the manufacturers seem to measure the entire length of steel protruding from the handle. If the case cited in the knife law forum is still good law, the actual cutting edge of most such knives will come in just under 3" and comply with the LA law.
When I have a good vocational/recreational reason for carrying a knife over 3", I usually go with a large or extra large CS Voyager. As before, the rationale is that I won't cry over a loss as much as I would with the custom Ryan. There are, of course, a ton of other good (and many better) entries in the >3" class. I sometimes carry a large Kelly Worden, CRKT factory Ryan Model 7 or other large CRKT models, Benchmade AFCK, etc.
Read the discussions here for a few weeks, search the archives for threads on models that interest you, then handle them. I'm sure that you will come up with at least a couple suitable choices .