Many people don't know that when you are booking your Fastpasses at Disneyworld, they actually have tiers.  Meaning in some parks you can only book one Fastpass out of Tier 1 when prebooking.  Then the other two of your prebooked Fastpasses will have to be out of Tier 2.  This can be frustrating and confusing if you don't understand which rides fall into each tier. Disney put the tier system into place to spread out the availability of the rides more.  Keep in mind if there is not a ride in Tier 1 that you are interested in, you can choose three from Tier 2.  Disney just wants everyone to get a fair shot at those high demand Tier 1 rides.

Avatar Flight of Passage

Navii River Journey

Kilimanjaro Safaris

Dinosaur

Expedition Everest

Primeval Whirl

It's Tough to be a Bug

Festival of the Lion King

Finding Nemo the Musical

Adventure Outpost Character Greeting

Rivers of Light

Most Popular Rides here are definitely Avatar Flight of Passage, Navii River Journey, Kilamanjaro Safaris, Expedition Everest.  Of Course, those fast passes to character meet and greets are always a good idea if that is something you are interested in.

Frozen Ever After

Character Greeting Spot

Soarin

Test Track

Epcot Forever Nighttime Spectacular

Mission Space

Spaceship Earth

Living with the Land

Turtle Talk with Crush

Journey Into Imagination with Figment

The Seas with Nemo and Friends

Pixar Short Film Festival

The most popular rides to fast pass here are Frozen Ever After, Soarin, Test Track, Mission Space and Spaceship Earth.  Again, meet and greets are worth it if you want to meet any characters.

Slinky Dog Dash

Toy Story Mania

Alien Swirling Saucers
Star Wars Smugglers Run
Rockin Roller Coaster
Hollywood Tower of Terror

Star Tours

Beauty and the Beast

Frozen Sing Along

Disney Junior Live on Stage

Muppet Vision 3D

Voyage of the Little Mermaid

Fantasmic

Indiana Jones Epic Stunt Spectacular

The most popular fast pass rides here are Slinky Dog, Toy Story Mania, Rockin Roller Coaster, Hollywood Tower of Terror and Star Tours.  The shows here are really great so if you are into live musical shows those are definitely worth a Fastpass

Big Thunder Mountain

Space Mountain

Splash Mountain

Seven Dwarfs Mine Train

Barn Stormer

Enchanted Tales with Belle

Dumbo 

Haunted Mansion

Jungle Cruise

Pirates of the Caribbean

Small World

Mad Tea Party

Magic Carpet Rides of Aladdin

Many Adventures of Winnie the Pooh

Meet Ariel

Meet Mickey

Meet Cinderella and Elena

Meet Rapunzel and Tiana

Meet Tinkerbell

Monsters Inc Laugh Floor

Mickey's Philharmagic

Tomorrowland Speedway

Under the Sea Journey of the Little Mermaid

There are so many rides in this park it is hard to choose.  The most popular rides for Fastpasses are Big Thunder Mountain, Space Mountain, Splash Mountain, Pirates of the Caribbean, Seven Dwarfs Mine Train, Peter Pans Flight, Small World and Haunted Mansion.  If you have a little one interested in princesses I would definitely recommend a Fastpass to meet those characters as those lines get LONG!

I hope this helps you break down the Tiers for Fastpasses in Disney World.  

XOXO

LEAH