I have been to DL, WDW, and Japan Disney... and each has some things that are the "best" to them.
I grew up in S.Cal. and went to DL many, many times! The best time is when it rains... Cal. folks melt in the rain... we went when we were in College and most people left! It was great!
I was just there Aug 23, 24, &25, which was a Tue-Thur. It was a solo trip and I could have done everything I wanted in only 2 days.. including eating at Blue Bayou, and at the Winery in CDA.
After going only to WDW for the last 10 years and not to DL, I was amazed to discover how small DL feels... and how much more crowded with attractions it is. I also decided that there are a few rides that DL does best. I like Pirates in DL best, then Japan, and then WDW. And Haunted Mansinon at DL. Buzz was to short in DL, and the Blasters can be lifted out and moved more, which I found made it harder to hit the Z's on and scored less then 1/3 of my WDW usual score! I think the Autoban/cars are best at DL. The new Space Mountain ROCKS!, it is fast, and very cool! DL has a wanta be Disney Quest in what used to be Caroseul of Progress... it was ok.
I also really, really missed some of the old, orginal attractions that are gone. The Tree House is now "Tarzan's Treehouse" not Swiss Family Robinson. The Submarines are gone. The Monorail is a short ride. Downtown Disney is a more commerical venture... I found it to be rather a joke, but it did have a few stores I would like to see at Fl. DTD- like Dept 56.
I will look forward to going back when my DD grads from USC(go Trojans...), in May. But if we had to move to the west coast I have told DH that the move package must include a big enought raise that I can come back to WDW for at least 7-10days each year, AND get a Disneyland PAP....
All in all I think I like WDW better, cause it is less crowded- land/size wise... and more to do with 4 parks and all the hotels to see. How ever if any one wants me to send me to DL on there dime... I'm willing to go!