Rapids and Sky Ride overhaul.
I think it'd be great for the entire length of the ride to be shrouded in tropical shrubbery, including the tunnel, with the addition of rocks, boulders, small waterfalls, and a few animatronic parrots perhaps, with Cariba-esque small tipping buckets with leaking pipes lining the roof of the Rapid-side of the tunnel.
London Eye replica pods, and lovely rethemed, clean stations. Towers Street, themed as an old airship base (like the current logo), all old and magical - Forbidden Valley with a theme radiating that of Airs, with cloud swirls and like the like (it could perhaps radiate the feeling of the Gardens also), and the Cred Street station with a magical, slightly sinister but 90's old school "Towers" theme to compliment the... Towers.