Disneyland ain't all that bad, don't listen to all the haters.
As a standalone park, it is better than Florida's Magic Kingdom equivalent at Disney World. It combines many greatest hits of the other Disney World parks with longstanding classic rides that all began there. And don't forget, Disneyland is the very first Disney park and you get the sense of history and some classic rides/stores/restaurants not found anywhere else.
Here are the top attractions, based on what's open:
Indiana Jones: Temple of the Forbidden Eye
-Get a "fast pass" for this ride right away, the lines often get ridiculously long as the day wears on. A great hydraulic buggy ride through a "Temple of Doom" type dungeon, complete with Indy helping you save the day.
Pirates of the Caribbean
-Better than the version at Disney World. A bit dated, but great atmosphere and you can spot all the references in last year's movie.
The Matterhorn
-Nice toboggan coaster, a Disneyland exclusive. Check out the bridge you go under at a high speed, a woman was decapitated there about 20 years ago.
Mr. Toad's Wild Ride
-Now a Disneyland exclusive (and the original), after its counterpart closed in Disney World. A fun little ride, and interesting for Disney because it seems like a drunk driving simulator. Always was better than Florida's version due to the heat effect in the Hell section (you'll see).
The Haunted Mansion
-Entirely different exterior from the Disney World version, though the inside is much the same.
Splash Mountain
-Cool off with this log flume water ride.
Star Tours
-The Star Wars motion ride that originated in Florida's MGM park.
Honey, I Shrunk the Audience
-This 3D attraction's days are numbered. Check it out while you can.
Peter Pan
-Cute ride in Fantasyland is longer and more elaborate than the Disney World version.
It's a Small World
-About five times bigger than the version in Disney World (which could be a good or bad thing), and the original ride that won the world's fair award.
Enchanted Tiki Room
-Cute animatronic parrots sing to you in a tropical pagoda. More fun than it sounds, and the only remaining original version... Disney World bastardized theirs with the obnoxious Iago character from Aladdin.
Storybook Land Canal Boats
-Ride on a boat past miniature settings from the animated movies. Do this at night, since the model cities are lit up then and look better, and try to be on the ride during the nightly fireworks (ask an employee when they are). It's the only ride that stops to observe the fireworks, and the ride host will direct you so that you don't miss a single one. The best location for the fireworks in the park.
Also check out The Blue Bayou for Disneyland's only full-service restaurant; it's inside the Pirates of the Caribbean and has great atmosphere and pretty good food. Make reservations or the wait can get long.
The Main Street U.S.A. drag after the entrance to the park is home to many charming little stores, all of which were replaced with one huge bland Disney store in Florida's Magic Kingdom.
New Orleans Square (near Pirates and the Haunted Mansion) is my favorite themed area, with Jazz bands and Louisiana architecture. There's no such area in Disney World.
As for Disney's California Adventure, it is a newer park and has less rides than Disneyland, but there are a few standouts:
Soarin' Over California
-Best ride in the park, a great hangliding simulator over the sights of CA.
California Screamin'
-Nice coaster, not insane, but a good sensation of speed.
Tower of Terror
-"The Twilight Zone" themed thrill ride from Florida's MGM is pretty intense.
The Maliboomer
-It's like Tower of Terror in reverse.
Malibu Madness
-Fun little coaster that derives thrills from sharp turns rather than big drops.
It's Tough to Be a Bug
-3D attraction from Animal Kingdom in Florida based on the "Bug's Life" movie.
Muppets 3D
-Another 3D attraction from Florida.
Hope you have a good trip!