Big Thunder is great as is and don't want to see it changed. I personally think it is superior to Everest in track layout, sights, and story.
Star Tours is already getting an update which I agree with.
The Jungle Cruise is a classic but it could use a new story with some new scenes. I know that WDI already has a plane crash segment designed and I would love to see it.
Peter Pan, IMHO, is a bit overrated. I still can't understand the 2 hour lines for a 90 second ride. I understand the novelty of flying above the ride is unique and exciting, but I would definitely like an update. I actually prefer Snow White. It is not the greatest ride but, the quick moving line mixed with spooky and nostalgic scenes works for me. Nevertheless, Fantasyland, particularly in Florida, could use a fresh coat of paint for all its' attractions including bringing the Japanese version of Pooh.
However, the ride that needs the most updating is Autopia. This is one of those attractions that has not withstood the test of time. When Disneyland opened, it was one of the star attractions. Yet, today it is little more than a incredibly large kiddie ride. It takes up a lot of space and has no theme. I would either raze the whole attraction and build something else or add a significant theme such as Tron light cycles or Cars. Either way, something needs to be done to it.
Peter Pan is still a great ride and I hope they never get rid of the flying clippers. The moving conveyor is very effective and efficient loading and unloading passengers.
I've always wondered why Universal Orlando didn't design the two seater for the ET ride. I never once felt like I was flying over the trees or city on a bike. You and eleven others load a platform and if you are stuck sitting in the middle, not only do you loose any affect of flying, you're unable to see over the sides.
From a "green" standpoint, those things must put out tons of exhaust not to mention the noise pollution. The attraction itself takes up a lot of prime real estate within Tomorrowland. Want to make it more "tomorrow"? Turn them into electric cars or hybrids. Make some car company sponsor it.
Jungle Cruise already did undergo somewhat of a change at DL by adding the Pirana scene and adding the explosion at the Gorilla Camp
So something among those choices that hasnt been done or announced yet would be to make Snow White and Peter Pan more realistic by changing the characters to actual, fluid Animatronics
If the question were for an "overhaul," then Autopia gets it. That ride is just awful in so many ways. It has no discernible theme. It smells terrible in and around the attraction. The cars are miserably uncomfortable and require 30 pounds of pressure on the pedal which leaves many kids unable to drive them (and the whole point is for kids to drive the cars, not the driving-weary adults). Driving on the freeway is neither futuristic nor desirable. And to top it all off, you have to drive on a pre-determined track. If Disney wants to see how to do a driving ride right then they should check out Volvo Driving School at Legoland. It's everything that Autopia is not, and the kids love it.
Star Tours is the next that should receive an overhaul. The queue is better than the ride.
The ride environment of JC is fine, but it needs a new script. Drop the jokes and give it a good story. For Halloween, I could imagine a great overlay with an Apocalypse Now theme and a Doors soundtrack. ;-)
This just has to end up in a Simpsons episode.
So, for me this vote comes down to either Jungle Cruise or Tomorrowland Speedway.
Jungle Cruise: I hate that this attraction is played strictly for laughs (BTW - the Great Movie Ride is sadly becoming the JC of DHS), but without a 21st century update the ride is a joke, so I understand why Disney goes for the corn. Additionally, the advent of Kilimanjaro Safaris pretty much rendered the ride obsolete as an animal safari, so what else can Disney do without a complete make-over? The Jungle Cruise is definitely a good candidate for an overhaul, but at least it is still uniquely Disney, and for that alone I give it a small measure of kudos.
The Tomorrowland Speedway on the other hand is the same car-on-a-rails experience found at every lame amusement park and county fair across the nation. It has no business in a Disney park and should be completely removed. An overhaul is probably not enough, but since the attraction always has lines (inherent to these types of slow-loaders) I am sure Disney still views it as a success. Therefore I would hope the attraction could at least get a futuristic re-theme, as well as some new, environmentally friendly vehicles. Right now it is just an eye-sore and a noise polluter, and something I hurry past on every visit.
Crash and burn, Tomorrowland Speedway....curse your vile fumes!
Peter Pans Flight!
The current ride at WDW CONSTANTLY has a MONSTER LINE!
Some might say that means "leave well enough alone. I say that it proves the popularity of the franchise (especially when it comes to Tink.
Gut the lame, 1970s funhouse effects. Make it state-of-the-art. Market it loud and long and they will CRASH THE GATES.