With young kids we love the Pooh ride. I know this one is not popular with most, but there is never a wait and often times the kids can meet Pooh and friends outside the ride. When Fantasyland is jam packed, this spot always makes my kids happy. Plus its near Splash, so we switch off with the older ones going on Splash while the younger ride Pooh.
Pooh
TOT (in july it had a 20 minute wait!)
Monsters Inc
Muppetvision
It's tough to be a bug
Mr. Toad (It doesn't get as much respect as it's closed WDW cousin)
The houses in Toontown
Golden Dreams (It truly is a great movie, you just have to watch it.)
these areas are overlooked as well:
Big Thunder Ranch
The Back Pathway around Grizzly River Run
The path over the Drop area at Splash Mountain
Roger Rabbit's Queue (Even if you hate spinning, get in line and ask to leave once you get to the loading area. You won't be dissapointed!)
Ditto - Roger Rabbit's CarToon Spin. Especially the queue if you've seen the movie. Not to mention the "portable hole" effect.
At DCA I'd say Muppet 3-D and Monsters Inc. The latter is a very well done - albeit short - dark ride that got a bad rap initially because of the long lines. Sure, it's not worth a 45 minute queue, but on it's own merit it's a great ride. And say hi to Roz for me.
Most overlooked ride: The Disneyland Railroad through the Grand Canyon and Primeval World
(An oldtime DL classic that doesn't even get mentioned on the maps anymore...)
Most overlooked attraction: "Say Hello to ASIMO" in Innoventions
(Featuring some truly magical technology. He even runs now!)
Most overlooked area: Snow White's Grotto
(Typically an oasis of serenity in the heart of the Park.)