Everyone has decent opinions here. I wouldn't skip most of the rides that are at WDW unless they are 10yrs old or newer. In many cases the DL versions are better.
Better at DL
It's A Small World
Pirates
Haunted Mansion
Space Mtn.
Splash (debatable)
Peter Pan
Pooh (shorter wait, better atmosphere)
Fantasmic! (when it's showing)
Fireworks (better than MK)
Enchanted Tiki Room
DL Railroad (Toontown or Tomorrowland to Main ST)
Mickey's Toon Town (vs. Toontown Fair)
Better at WDW
Big Thunder
Jungle Cruise (depending on the skipper)
Innoventions
DL exclusives you can skip
Tarzan's Tree House
Toontown rides (Except Roger Rabbit)
Casey Jr. Circus Train or Storybook Land CAnal Boats (only do 1)
Pinocchio
Columbia
Snow White show (I think it's gone)
Astro Orbitor
Same at Both Parks (skip 'em)
Honey I Shrunk the Audience
Tower of Terror
Soarin'
It's Tough To Be A Bug
Autopia
Mad Tea Party
DCA Must do's
California Screamin'
Grizzly River Run
Aladdin Show
Maliboomer
Mulhallen Madnes (sp?)
I suggest doing DL in the early AM, head to DCA around 1-2ish, and back to DL til closing.
Also. Not many people are going to agree with this, but you've been to WDW, you probably love WDW. I do to, but DL is my home. Unless you go for one meal, or after DL closes, SKIP DOWNTOWN DISNEY!
WOD is nice but narrow and you can get better stuff inside DL.
Marceline Confectionary is also nice, but for the most part, the rest are just cookie cutters of places you have probably been to before.
Everyone will agree that WDW's DTD is by far much better than DL. Like Walt Disney said himself, they "have the blessing of size" that DLR just doesn't have, and nowhere is it more noticeable than DTD.