In the spirit of sharing all things grub-related, here's a really extensive listing of Hawaiian eateries in Southern California (LA, the OC, and San Diego).  Be forewarned that this list is several years old, so i'm not sure if all of these are still around.  But please post comments to let me know if some are gone and i'll update this list.
d'bugga ono!!!!!
BEST OF HAWAIIAN FOOD
http://alohaworld.com/platelunch/
Los Angeles County 
Aloha Cafe Hawaiian Restaurant 
1944 S. Atlantic Blvd, Monterey Park, CA 91754-6302 
Phone: (213) 728-9110 
         
Aloha Food Factory 
2990 W. Valley Blvd, Alhambra, CA 91803-1819 
Phone: (818) 308-0215 
Aloha Teriyaki
4834 W. Rosecrans Avenue (corner of Rosecrans and Inglewood), Hawthorne, CA
Phone: (310)644-2330
The Beach Hut 
3920 Highland Avenue, Manhattan Beach, CA 90266
Phone: (310) 545-8911 
The Beach Hut II 
1342 Hermosa Avenue Hermosa Beach, CA 90254 
Phone: (310) 376-4252 
B-Man's Teriyaki & Burgers
3007 E. Huntington Drive #102, Pasadena, CA  91107 (corner of San Gabriel Bl. 
& Huntington Drive)
Phone: (626) 568-0386 
Bob's Hawaiian Style Okazuya 
16814 S. Vermont Avenue, Gardena, CA 90247-5619 
Phone: (310) 515-2250 
Bruddah's Hawaiian Foods 
1033 W. Gardena Blvd, Gardena, CA 90247-4957 
Phone: (310) 323-9112 
Cherrystones Grill & Grotto
15501 S. Vermont Avenue, Gardena, CA 90247-4100
Phone: (310) 329-8200
Gardena Bowl Coffee Shop
15707 S. Vermont Avenue, Gardena, CA 90247-4328
Phone: (310) 532-0820 
Golden Ox 
23401 S. Normandie, Torrance CA 
Phone: (310) 539-3845 
Hang Loose 
1126-30 Redondo Beach Blvd., Gardena, CA 90247 
Phone: (310) 532-6310 
Harry's Aloha Chop Suey
1721 W Redondo Beach Blvd, Gardena, CA 90247-3223
Phone: (310) 324-4231
Hawaii BBQ
16649 Sherman Way
Van Nuys, 91406
Phone: 818-780-8838
Open Daily: 10:00am-9:00pm.
Hong Kong Gardens (Deli in the back)
21718 Vermont (cross street Carson) Gardena, CA 90247
Phone: (310) 320-8802 
Kappa Coffee Shop 
15116 S. Western Avenue, Gardena, CA 90249-4313
Phone: (310) 324-6129 
Kau Kau Korner (Inside Marukai Market Food Court)
1740 W Artesia Blvd., Gardena, CA 90247-3233
Phone: (310) 515-5110 
Kings Hawaiian Bakery & Restaurant 
2808 Sepulveda Blvd, Torrance, CA 90505-2803 
Phone: (310) 530-0050 
L&L's Hawaiian BBQ
Puente Hills Mall 1600 Azusa Avenue #169J, City of Industry 91748 
Phone: (626) 581-3338 
The Loft at Punaluu 
15607 S. Normandie Avenue, Gardena, CA 90247 
Phone: (310) 523-4191 
The Loft at Lahaina 
17311 Yukon Avenue, Torrance, CA 90504-2316 
Phone: (310) 523-3373 
The Loft 
20157 S. Pioneer Blvd., Cerritos, CA 90715 (in Ralph's Center)
Phone: (562) 402-3538
Lorri's 
16400 S. Western Avenue, Gardena, CA 90247-4636 
Phone: (310) 329-4441 
  
Miki Chan's Okazuya 
2529 Via Campo, Montebello, CA 90640-1806 
Phone: (213) 722-0519 
Pacific Islander QSR
2540 S. Figueroa Street (at Adams), Los Angeles, CA 90007
Phone: (213) 746-2888 
  
Paradise Okazuya 
1631 W. Carson Street, Torrance, CA 90501-3846
Phone: (310) 328-5345 
Rascal's Eat In Take Out
15482 S. Western Avenue, Gardena CA 90249-4325
Phone: (310) 516-8814
Rascals Teriyaki Grill
5111 Torrance Blvd., Torrance
310 542-0022
Rutt's Inn
12114 Washington Blvd., Los Angeles, CA 90066
Phone: (310) 398-6326
Shakas
2300 S. Garfield Avenue, Monterey Park, CA 91754-7200
Phone: (213) 888-2695 
Spike's Teriyaki Bowl Restaurants 
Look for a location near you! 
Teri's Place
2140-D Artesia Blvd., Torrance CA 90504 ( In the Del Wee Shopping Center 
Strip Mall)
Phone (310) 327-2006 
Teri Hawaii 
1425 W. Artesia Blvd. #34 Gardena, CA 90248 
Phone (310) 327-0307 
Teriyaki Magic
3901 Ingelwood Avenue #105, Redondo Beach, CA Near the 405 Frwy; between 
In-n-Out and Petco
Phone: (310) 973-3500
Three Brothers Drive Inn
23722 Western Avenue, Harbor City, CA 90710-1321
Phone (310) 326-3843
Orange County
Aloha Chicken
5123 Ball Road, Cypress, CA 90630-3610
Phone: (714) 821-3610
Aloha Chicken
10488 Valley View Blvd., Buena Park, CA   90620
Phone: (714) 826-6672
Fuji's (Behind Coco's, near Edinger Street, west of Beach Blvd.)
15885 Gothard Street, Huntington Beach CA 92647
Phone (714) 891-6066
Island Grill
4390 Katella Avenue, Los Alamitos, CA 90720-3565
Phone: (562) 431-4696
Jr's Kitchen
5633 Lincoln Avenue, Cyrpess, CA
Phone: (714) 229-0432
L&L's Hawaiian BBQ
19692 Beach Blvd.,Huntington Beach, CA 92648
Phone: (714) 968-1898
Matiki Island Barbecue 
3070 W. Lincoln Avenue #Q, Anaheim, CA 91801 
Phone: (714) 821-5228 
 
San Diego County 
Da Kine's Plate Lunch - Owner Nelson Y Ishii 
4120 Mission Blvd. #208 (The Promenade), San Diego, CA 92109 
Phone: (858) 274-8494 
Da Kine's Plate Lunches - South Bay
1635  Sweetwater Road #H National City, CA 91950
Phone: (619) 474-8494 
Island Boy Grille
10066 Pacific Heights Blvd., Sorrento Mesa San Diego, CA
Phone: (619) 452-7708 
Island Boy Grille
554 4th Avenue, San Diego, CA 92101 in the Gaslamp Quarter 
Phone: (619) 702-8343 
Kealani's
137 West D Street, Encinitas, CA 92024 
Phone: (760) 94-ALOHA
Sushi Kaisen
1910 Oceanside Blvd., Oceanside, CA
Phone: (760) 757-1484