The Walt Disney Travel Company (WDTC) packages include preferred seating at three of the DCA shows: Aladdin, It's Tough to Be a Bug, and Muppets 3D. You can book through them directly, or use travel agents who book through them like
Dreams Unlimited Travel & AAA.
If you pay for your entire package with your Disney Visa, you also get preferred seating at Snow White-An Enchanted Musical, premium viewing for one of the parades at either
Disneyland or California Adventure, and a Disney tote bag.
I've been at preferred seating for Aladdin & Snow White. You show your voucher to the CM, and will be directed to wait to be seated in a roped off area. You'll then be seated before everyone else. In Aladdin, we had our choice of the Orchestra section. In Snow White, we sat about halfway back, and off to the side, below the Enchanted Cottage treats snack stand (left side).
I once went on a holiday tour at Disneyland, and got premium viewing for a parade - it was over by It's a Small World -- we stood, but had a perfect view of the parade. I don't know if this is the premium viewing spot.