I have vertigo and get motion sick everywhere, even in the bathtub and swimming pools. When at WDW, I take one Bonine every morning. Bonine is a different drug from Dramamine; I find it doesn't make me as tired all the time, they are chewable, and only need to be taken once a day. I need this just to handle the tram in from the parking lots! I would NEVER go to WDW without my Bonine! So, here's my list:
THINGS TO AVOID AT ALL COSTS!! Mission Space (both sides), Space Mountain, Barnstormer (really bad), tea cups, Astro Orbiter (WORST of the bunch, even DD14 won't ride this one and she rides EVERYTHING, EVERYWHERE), RnRC, Star Tours, Primeval Whirl, Body Wars (if it's open). AVOID RIDES WITH SIMULATORS!!!
ONE RIDE WITH BONINE: Soarin' (close your eyes if it makes you queasy, the seat isn't moving at all), BTMRR, TestTrak, Dumbo, Aladdin's carpets, Cinderella's Carousel, Kali River Rapids, and Triceratops spin. More than one ride will make me nauseated, and it lasts for several hours (long enough to ruin the day).
I choose to skip Splash, ToT, RnRC, and Everest, but that's because I don't like the falling feeling on roller coasters. I have ridden Splash mountain and don't get motion sick at all, but have never done the other 3.
Be careful watching the movies!! I get queasy while watching most of the films like Mickey's Philharmagic, WS films from the different countries, Timekeeper (closed now)- anything with big moving pictures, or that play on a circular screen. The good thing about these are that the seats don't move at all- just close your eyes if you feel queasy!
I've never had a problem on Spaceship Earth, Maelstrom, or the Safari. I've never been on Honey I Shrunk the Kids, Liberty Belle, or Dinosaur. I ride the monorail, ferries, train around MK, parking lot trams, and Friendships but that's with the bonine under my belt.
I am OK on everything else, I think, but remember that I always take one Bonine as soon as I get up each day. good luck!!