I'm not really a big roller coaster fan so when I go to these parks unless it's a gentle ride like Small World I pretty much stick to the shows and parades. Hollywood studios does have alot of very popular rides like Rockin Roller Coaster or the Tower of Terror:
There's also the hugely popular Pixar area home of Toy Story Mania and anytime I have been in the park the wait time for this ride is 2 hours which is a little crazy I think:
One thing about Hollywood Studios that over time even though some of the shows changed or got updated or even some new rides and attractions were added to bring the park up to date with current Disney favourites there is still hits of the old MGM studios for example when I was little on my first Disney trip I got a picture beside this boat:
It is still in the Park in the same spot and is home to a counter service food/ice cream place now. The building behind it has changed it's attraction to the more up to date America Idol Experience though:
For this show guests can audition for to be part of the America Idol Experience then through-out the day they hold the audition shows in front of other guests and three people will sing at a time. At each show the audience pick a winner then at the last show of the day all the winners sing and whoever wins that gets a golden ticket to skip the line at a real American Idol audition. Pretty cool idea if you're into those shows:
Another old favourite that was there on my very first trip and has only been updated prop wise since is the Studio Backlot tour. They start off showing you how a movie scene is filmed:
You then walk through an area filled with tonnes of props from various Disney movies and cartoons:
Before finally boarding a tram to Catastrophe Canyon:
From there another old favourite is Muppet Vision 3d. Of course Muppets have made their comeback recently with the Muppet Movie being released in February but this show and whole area of Hollywood Studios is so cool for any Muppet fan. It starts outside the Theatre with the Muppets Fountain:
There's also Gonzo hanging from a Clock:
The show itself is true Muppet style fun in 3D and then afterwards you come out to find the Muppets shop which again is wonderfully themed full of Muppet stuff from entrance to exit:
Of course if you're more into Extreme Stunt Shows then the Light, Motor, Action show might be more your style. This is a fast paced show involving speeding cars, gunshots, motorbikes, speedboats and even Lightening McQueen:
Again being Hollywood Studios the whole idea of the show is to show you how the vehicle stunts are done for the movies:
For the Princess lovers there's Voyage of the Little Mermaid which is pretty much a shortened version of the movie:
and sticking with shortened versions of the Disney movies there's also Beauty and the Beast - "live on stage." 
At various times as well there's dancing/musical shows reflecting whatever is popular at the time. I've seen High School musical 2 and 3 and last year the show had changed to Disney Channel Rocks:
