I investigated this subject in the past.
It depends very much on your personal tastes/preferences of course, but the best two apple varieties (if you like tart and flavorful) are Cox's Orange Pippin and Ashmead's Kernel. Going down the line, to sweeter bigger apples, you have Envy and Mutsu. Opal isn't bad either.
Now, for zone 10b, that's another matter entirely.
There was a field study done in Irvine, CA (also zone 10 ) that found that many varieties of apple could actually produce satisfactorily, even though they were rated much higher in chill requirements than what they were getting at that location. It's just these apples tended to flower and fruit throughout the year than at one time.
I can copy and paste it for you, if you're interested:
The latest reports have shown that apples tend to be more adaptable to lower-chill areas than was previously thought. A field test by Tom Spellman of Dave Wilson Nursery showed that several apple varieties rated for 800 chill hours could grow just fine in Irvine (located in coastal Southern California, which only gets 50-100 real chill hours). The following apple varieties did surprisingly well: King Tompkins, Braeburn, Gravenstein, Cox's Orange Pippin. The trees tended to flower and set fruit throughout the year rather than a specific season.
The results might have had something to do with the fact that the coastal influence has a moderating effect on temperature, and in the winter it rarely ever gets above 65 F in this region, higher temperatures being very detrimental to effective chill accumulation. In other words, the same moderating influence that prevents there from ever being any chill hours below 45 F may be, paradoxically, the same influence that allows the trees to grow well even in the absence of chill hours below 45 F.
Of course, if you are talking about real low chill apples, that's another matter, and I don't think there are a lot of different options.
From what I hear, the low chill apple varieties just taste okay. But then again there's nothing like an apple right off your own tree, and it will taste better than most of the apples from the supermarket.