I did a google search and found the list below. A short list of what does well in our area would include...
Cercis occidentalis (Calif Redbud)
several types of Eucalyptus
Gingko biloba
Jacaranda
Lagerstroemia amabilis (crape myrtle)
Liquidambar
Avocado
Pine
I personally would not plant Eucalyptus or Pine trees if the area is upwind of, and fairly close to your house. I've had recent bad experience with large limbs from both of these types of trees breaking off in Santa Ana winds (like today). The Pine tree limb took out a brick wall immediately next to my house. I have clay soil in my backyard, and my Jacaranda (a volunteer) is doing fine. It has grown about 16 ft. in 4 years.
After clicking the link, click the green bar in the upper left hand corner that refers to oak root fungus. It wouldn't link directly, for some reason.

Here is a link that might be useful: East Bay Nursery

If you're looking for a fruit tree, consider the pineapple guava: http://www.desert-tropicals.com/Plants/Myrtaceae/Feijoa_sellowiana.html

It doesn't need pruning except for shape, no spraying, drought resistant, delicious fruit that drops off the tree when ripe without making a mess, lovely red flowers.

Thanks a lot for the advice. I'm thinking Jacaranda right now, but that could change...

Don't plant jacaranda if there are any hardscape areas (driveway, patio) under the tree - the flowers, though beautiful, are sticky & make a mess when they fall. Also, crape myrtle is subject to powdery mildew near the coast, and liquidambar has invasive roots and drops prickly seedballs.

Ginkgos are beautiful but not fast growers.

Not a true tree, but herbaceous: have you ever considered bananas? They love humidity, and there are several varieties such as Goldfinger which get to your required height within about 2-3 years, are disease-resistant, give a great tropical look, and produce big bunches of really delicious fruit.

Nick:

A "fast-growing", "15-20" "tree" is rare (impossible?), much less one that is oak-root fungus resistant, tolerant of heavy clay soils, and fog loving. Trees, by most definitions, get "over 20 feet", to differentiate them from shrubs.

If you want "fast", "clay soil tolerant", oak-root fungus resistant AND are willing to accept a taller tree, there's:

Arbutus ÂMarina -- Hybrid Strawberry Tree
Cercis siliquastrum -- Judas Tree
Cryptomeria -- Japanese cedar
Eucalyptus cinerea -- Ashy Gum*
Fraxinus angustifolia ÂRaywood -- Raywood Ash
Geijera parviflora -- Australian Willow*
Maytenus boaria -- Mayten Tree*
Melaleuca styphelioides -- Black Paperbark*
Pinus -- Pines (many)*
Pistacia chinensis -- Chinese Pistache
Pittosporum rhombifolium -- Queensland Pittosporum
Quercus ilex -- Holly Oak

(if your coastal garden is subject to typical coastal wind and salt spray, consider those marked * above)

If you want the same qualities and are willing to prune to train, there's some large shrubs and shrubby trees that make nice 15-20 foot trees:

Acacia longifolia -- Bush Acacia
Acacia verticillata -- Prickly Moses
Cryptomeria japonica 'Yoshino' -- Plume cedar
Ilex x altaclarensis 'Wilson' -- Wilson's Holly
Myrica californica -- Pacific Wax Myrtle
Pinus cembroides -- Mexican Pinyon Pine
Pinus contorta contorta -- Beach Pine
Pinus thunbergii -- Japanese Black Pine

And if you want a fruit tree, the best oak-root fungus resistant ones for heavy soils are fig and persimmon. Out of the wind.

Joe

We are a bit coastal south of you, but the Jacaranda here needs a lot of heat in order to flower. Otherwise, it can stay leafless for quite some time, especially with cool fogs during summer.

They line San Diego city streets and look nice in the late summer, but get more heat and reflected heat from streets and side walks.

I like the macadamia tree - for fast growing and great looks all year long. It has plumes of pink flowers several times a year, followed by ripening nuts. These are great toasted and in recipes for cookies, etc.

It seems to like our coastal zone 23/24 location.

Bejay

Jacaranda gets way bigger than 20'.

I just got an Agonis flexuosa 'After Dark', which is somewhat smaller than the species, supposed to get 20'x20' max. It has burgundy leaves. It is evergreen.

I've also got Dodonea viscosa limbed up as a small tree. It grows very quickly and is a tough plant.