Here are some of my favorites:
Its Tough to be a Bug
Honey I Shrunk the Audience
Probably the greatest 4D attraction I have ever been on is Spiderman!
First of all, they get you out of the elements which is great if it's raining, or if it's 90+ outside you get an Air Condition break.
A lot of the time there are pre-shows which help to mask the waiting time for the actual attraction. Muppet Vision 3-D has a very entertaining pre-show, especially if you are a fan, and it runs pretty much the length of your wait, which is great!
Although some of the older shows are showing their age these days, it's still lots of fun to sit with a large group of people and have a communal experience, reacting to the various 4-D gags and elements designed to get a reaction from the crowd.
Even though 3-D seems to be all the rage again in Hollywood (god help us), don't expect theaters to start installing all the bells and whistles that seperate theme park 4-D adventures from their bloated, higher budget, Tinsel Town cousins. Fog, props, water, lasers, smells, live actors, true stereo-scopic surround sound, animatronics, seating with various effects built into them, air cannons, highly detailed and themed theaters and pyro effects are par for the course with the more cutting edge 4-D shows. All of these elements combined along with the on screen 3D really help to bring the audience into the middle of the action, and create a far more immersive experience than 3D delivers alone.
All in all, if you normally pass by 4-D shows when you visit a theme park, you very well could be missing out on one of your favorite all time attractions and you don't even know it. At least once, you owe it to yourself to give them a try. If you don't like it, then you don't have to worry about wasting any of your valuable time on them the next time you visit. If you do end up enjoying them, congratulations, you've just expanded upon the fun you can have when visiting your favorite theme parks.
From a dimensional standpoint, the fourth dimension is a difficult concept to grasp and should not be used in 3D attractions. It's misleading. People sometimes interpret the "4th" dimension in these attractions as off-screen effects (e.g. water spray), which saddens the nerd in me.
But I have to add-- don't visit the Pirates one at Busch Gardens-- I think that's the worst 4D I've ever seen. The acting? Blah. The effects. Ehh. The 4D? Doesn't really utilize it.
4D is the same as 3D but there's one more.
Walt Disney World's Magic Kingdom
Disney's Animal Kingdom
Disney's Hollywood Studios
Disney California Adventure
Universal Studios Florida
Universal's Islands of Adventure
Universal Studios Hollywood