I go to WDW because it's closer now.. but I lived 10 miles from DL for 4 years and went there over 200 times. I would be hard pressed to choose, but I think I would chose DL.
Some of the rides at DL are better:
Space Mountain
Pirates
Splash
Peter Pan
The Monorail is more of a ride than transportation.
DL has rides WDW MK doesn't:
Mr. Toad!
Snow White!
Alice
Matterhorn!!!
Roger Rabbit
Carsland RSR beats Test Track for me
Storybook Land Canal Boats (At night it's really cool!)
Indy
Grizzly River Run better than Kali River Rapids
As someone mentioned previously, DL, DCA, and DTD are all doable in one day BY WALKING.
World of Color is AMAZING!
Fantasmic is better at DL
Star Tours is in DL, not a separate park.
However, staying onsite at DL is more expensive than WDW (if you count Values, which DL doesn't have), but cheaper with the offsite hotels than values.
Crowded days at DLR feel WAY more crowded than WDW because of the compact size of the park.
WDW has Rocking Roller Coaster and Everest - but they are in separate parks.
WDW has more food choices and when you're in WDW, you are really in your own world.
I would still choose DLR.
