Okay, if you are doing one day get a park hopper ticket. But, be aware that California Adventure Park closes early that night for MTOT (Mickey's Trick or Treat Party). Take advantage of Fast Pass. Make sure you are holding a fast pass when you use the most current one. If it appears there is a long line for Pirates or Haunted Mansion, walk away and come back in 15 minutes. The line will miraculously clear. Either way, it never takes more than 20 minutes in either of these lines. Tower of Terror is another que line that moves VERY fast. Don't worry at the listed wait times. Soarin and California Screamin have single rider lines - there may be others but these are the two that I have used multiple times. Toy Story Mania does not have fast pass. If you want to go on it wait in line. The line moves relatively fast, and the que is fun. I don't believe they have a single rider entrance, at least they didn't when I was there last. Indiana Jones Adventure is a must see for WDW natives as its a ride that doesn't exist at WDW. Also, wait in line for Matterhorn. No fast passes but the nature of the line makes it look like it will take a long time. . .it doesn't really. Nemo Subs is a long line, the wait is longer. I don't wait for it.
Fast Pass must do's - Space Mountain, Splash Mountain, Indiana Jones Adventure, Big Thunder Mountain Railroad, Roger Rabbit's Cartoon Spin, Buzz Lightyear's Space Ranger Spin, Soarin and California Screamin(if you don't want to do single rider), and Tomorrowland Autopia.
Hmmmm, I could post more but maybe you should ask questions so I know what it is you like to do.