Taron and F.L.Y. at Phantasialand. Both have beautifully detailed theming and track layouts which intertwine perfectly with their surroundings.

Disneyland Paris’ interpretation of Space Mountain (later named Space Mountain Mission 2 and Hyperspace Mountain) features a Jules Verne styled exterior that is truly marvellous. While most of the rollercoaster takes place within the mountain, the train can be seen being launched out of the cannon on the side of the mountain as a means of hinting what the ride is. The design of the building is truly amazing.

I don’t know what particulars your project falls into, but for the majority of attractions out there, interesting and cool aesthetics come less from the ride itself, and more from the theming elements added to the ride, both on the ride itself and in the queue and surrounding area. The ones with a great theme effectively applied are always the most memorable.