The basics - the parks are REALLY close together, which is a surprise to most WDW vets.
Also, you're visiting during Halloween Time, which outside of the holidays, is the best time of year. Haunted Mansion has been taken over by Jack Skellington (try to ride in the morning, they no longer distribute Fastpass for this). There are tons of Fall treats all around the park, and be sure to go to the Big Thunder Ranch Jamboree. The characters roam around in Halloween costumes, there are free carnival games, meet & greets with Villains, pumpkin carvers and more. It's a great spot to cool off in the middle of the day.
Attractions that are unique to DL and worth visiting (or * = different than WDW's version and worth the ride):
Alice in Wonderland
Storybook Land Canal Boats
Casey Jr. Circus Train
Mr. Toad's Wild Ride
Pinocchio's Daring Journey
Snow White's Scary Adventure (look up when you're outside the attraction, and touch the apple on your way in)
It's a Small World*
Peter Pan*
Matterhorn (be warned, the ride vehicles are a TIGHT squeeze, and if you have back issues, you'll really feel them afterward)
Space Mountain*
Pirates of the Caribbean*
Big Thunder Mountain*
Haunted Mansion*
Indiana Jones
Jungle Cruise (since it's the original)
Toon Town, at least a quick walk-through, even if you skip Roger Rabbit's Cartoon Spin
A FULL trip around on the train (specifically between Tomorrowland & Main Street station, but it's worth it to do the loop). Also, if you get there FIRST thing in the morning, go up to the Main St. station and ask a conductor if they're giving tours of the LilyBelle that day. If they are, they'll schedule a return time for you.
Also, in Innoventions (Tomorrowland) you can meet Captain America & Thor, if that's something you're into.
Over in DCA, Radiator Springs Racers & World of Color are not to be missed. You'll want to get RSR FP's FIRST thing in the morning. They also have a single rider line which moves pretty quickly, if you don't mind not being in the same vehicle as your wife. For WoC, they distribute Fastpasses at Grizzly River Run, or you can book a dining package (I recommend Carthay Circle lunch, it's pricey, but cheaper than their dinner and oh so good).
Try to be in Cars Land during the lighting ceremony one night (at dusk, you can ask a cast member for the specific time).
Oswald the Lucky Rabbit is now doing meet & greets at the entrance to Buena Vista Street, which is pretty cool. Especially since he hasn't been introduced to WDW just yet.
Pretty much all of the quick service options are good, and offer much more variety than at WDW. Each restaurant has something different to offer - I'd take some time and check out the menus beforehand. Touring Plans site seems to have the most up-to-date info, but there's also info here on WDW Info and on Allears.
There is a LOT more entertainment all around
Disneyland, so be sure to stop and soak in the atmosphere every now and then.
Hope you have a great trip!
