I am planning a trip to Orlando for New Years. I am wondering which park is better - Universal Studios or MGM Studios. Which park is better for someone in their 20s? Also, which park has more roller coasters and how many do each have? (I'm not a big roller coaster person). Finally, since I am going during the winter, will it be too cold in Orlando to plan on going to the water parks?

Islands of Adventure has the most rollercoasters, including Dueling Dragons and The Hulk. Also big water rides like Jurassic Park and Dudley Do-Right. The "old" part of Universal has all the disaster movie rides, and E.T. and Back to the Future. MGM's scary rides are only Tower of Terror and Rockin Roller Coaster. Normally I'd say IOA is best for a twenty-something, but if you don't like roller coasters . . . The weather will probably be cool. You may get one or two warm days; listen to the weather reports and plan once you get there!

I live in Orlando and can guarantee you that no one knows what the weather will be like around New Year's! I've seen it 28 degrees and I've seen it 70 degrees and you just never know. The water parks have heated water and you might luck out with a relatively warm day.

In my opinion Universal's Islands of Adventure beats out Disney in the amusement field in every single way.

Been to both ( MGM was years ago however, before the two attractions mentioned above ). Would agree that Universal is best...

I am from England and have just returned from my 7th trip.
I would say Universal is easily the best. As both US and IOA are right next to each other you can walk from one to the other. Be aware though that some of the best rides at IOA are water rides, you may not fancy getting wet if the weather is cold. We didn't mind becasue it was 90 degrees!
US is looking a little dated now, itr could do with a few new rides, attractions like 'lucille -a tribute' should be knocked down and replaced with something newer..but if you have not been before it is a great park.

I've been to both, and would pick Universal Studios. I would do Universal and Islands of Adventure since they are right next to each other. Islands has roller coasters & water rides versus Universal has more simulator rides which are really nice! You can get passes to go to both parks at a discount. We did Islands for 1/2 the day (morning) and did Universal during the other half.
Have fun!!

Definitely, Universal and Islands of Adventure. Disney is so very rated.