I like the Space Mountain at WDW more. It has the better entrance and exit queues. It has a store attached that's miles better than the both the small wall in the exit of the DLR version that doesn't carry much stuff and Star Traders which is really for Star Tours. You can get actual Space Mountain merchandise at the WDW version. The ride mechanism is better because it's a smooth track version of the Matterhorn. The climb up is better complete with the two Daft Punk looking guys. I even like the music better. The only thing it lacks is a good loading area. The exit queue is what Horizons used to be and I'm thankful it still exists.
I'll also argue the Haunted Mansion is better at WDW for the same reason, minus the shop. The entrance queue is better. The first portion where you load is more dramatic. DLR gets points for the Hatbox Ghost being in the right place. It's a more striking building than just a New Orleans manor. At Halloween time, they have characters on the lawn in front of the queue which adds to the flavor. Now New Orleans Square is a lot better than Liberty Square and the Mansion fits a lot better in NOS. The whole Liberty Square area is going to look weird next to a giant Cars land.
Guardians and Tower are not comparable IMO because they're two rides going for different things. Guardians is meant to be thrilling and be a fun ride. Tower of Terror is meant to scare you. The walk up to the Tower of Terror is better as is the outer queue. I like both equally but for different reasons.
Pirates is better at DLR by a wide margin. You simply can't beat the ambiance of the opening section with Blue Bayou.