Mummy > Cosmic Rewind > Space Mountain > Gringotts > Rockin Rollercoaster
Mummy is really great, from the excellent track layout to the wonderful queue (and the reasonable wait times), there is a lot to love about the Mummy.
Cosmic Rewind is so much fun! But the preshows are a real drag on the experience. So it can't take the top spot.
Space Mountain is a ton of fun, but I miss the moving walkway at the exit, and the renovation about a decade ago where they enclosed the queue was a real hatchet job.
Gringotts may have the best individual moment of any of these, and the queue is quite grand. But all the "stop so the characters can have three paragraphs of dialog" really hurts it.
Rockin Rollercoaster is fun, but not nearly as good as Avengers Assemble: Flight Force at WDSP with the same layout.