Toy Story Friends
From Disney's Hollywood Studios Wiki
 Buzz Lightyear
Buzz Lightyear is a toy Space Ranger with cool gadgets, such as a laser and jet pack. Andy receives Buzz as a present and quickly becomes attached to him, however Buzz, not realizing that he is in fact a toy, but rather the real Buzz Lightyear, is constantly attempting to repair his ship, which is actually the box he was packaged in, and contact Star Command. This quickly annoys Woody, who was Andy's Favorite toy until Buzz came along. He eventually discovers that he is, in fact, a toy, which sends him into a spiraling depression, until Woody convinces him that being a cool toy is better than being a Space Ranger, which eventually allows the two to become close friends. Buzz eventually embraces being a toy and has his own unique adventures with his new found friends. He is voiced by Tim Allen.
Woody is a Cowboy Doll and Andy's favorite toy. Being so he is the "leader" of all the other toys. When Buzz Lightyear came along that eventually through everything out of whack, and this made Woody very jealous of Buzz. But after settling their differences, they became good friends. In Toy Story 2, Woody gets kidnapped by a toy collector and discovers that he is actually from a 1950's TV Show, called woody's Roundup. He becomes obsessed with the idea of being an actual cowboy, and it is only when Buzz and the other toys come to save him, and Buzz uses Woody's own words about how it's better to be a toy against him, that he comes back to his senses. Woody is voiced by Tom Hanks.
 Jessie (Occasional)
Jessie is a Cowgirl Doll who is another main character in Woody's Roundup. Jessie belonged to a little girl, apparently in the 60's-70's, who out grew her, and eventually left her, as well as a box of some other old toys, sitting on the side of the road. She eventually was found by a toy collector, named Al, and spent most of her life just sitting in a case. Once Woody arrives, however, Jessie gets very excited, and she tells him about the TV Show, and eventually informs him that Al is selling his collection to a Tokyo toy Museum. Once Buzz shows up to save Woody, Jessie agrees to help them all get back to Andy's house, after they tel her that Andy has a little sister.
Buzz and Woody have actually been featured in the park for quite some time, and are some of the very few characters to be featured in three parades, Toy Story - The Parade, Operation: Toy Story, Disney's Stars and Motor Cars Parade, and, most recently, the Block Party Bash.
 Other Studios References
All three of these characters are also in Toy Story Midway Mania!. All three are featured at the beginning in the Pie Toss Practice Booth and the end where they show you the points. Woody and Jessie host the Rootin' Tootin' Shootin' Gallery, and Buzz hosts the Flying Tossers game.
A few of the items fro Al's collection can be seen at the Hey Howdy Hey Take Away.