Unfortunately, big discounts are hard to come by at
Disneyland. The main ones are Disney Club and
AAA. I'm not sure about AP.
Also, I recently booked a package through DU, and they informed me that DL no longer offers room only discounts for DC (not sure about AAA). They only discount packages, 10% off the room portion of the package.
DL's packages seem to be more valuable than WDW (in general) though. I requested a quote for room only and quote for package which included 3-day hoppers for 2 adults, and room only was only $100 less (package included a DC discount). ONE park hopper is over $100, so in this case, we saved. DC saved about $100 as well.