Andrew "Andy" Davis is the hero in Toy Story series. He always loves to play with his toys.
In his early childhood, Woody has been Andy's favorite toy until he receives a Buzz Lightyear action figure for his birthday, and quickly becomes fascinated with him. He has originally intended to take Buzz to Pizza Planet, but takes Woody since he can't find Buzz (due to Woody accidentally knocking Buzz out of the window a little earlier). Unfortunately, he has lost both toys when he comes back home from dinner, and feels afraid about leaving them behind on the day they move to a new home. However, Woody and a reformed Buzz, after escaping Sid, manage to catch up to Andy by soaring and flying through the air (with the help from the rocket that Sid has taped to Buzz in order to destroy him), dropping through the open sunroof of Andy's minivan and landing in an open box right next to Andy, startling him, but finally making him happy once again now that he has found them at last (Andy's mom assures that they had been right where he had left them). Since then, both of the toys have become his favorites to play with.
At the end of the movie, Andy had received a puppy (whom he named Buster) for his Christmas present.
Toy Story 2
In the sequel, Andy is shown to have grown up slightly. He is an 10-years-old minor character in the movie as he only appears for a short time at the beginning and at the ending. However, during his short appearance, it's easy to tell that he still loves his toys and that the toys still feel the same about him. When he accidentally causes a rip in Woody's arm, his mom feels sorry for him, stating that toys don't last forever, a sentiment fueled by Stinky Pete who wants Woody to go on display and by Jessie who tells Woody of her past owner who grew up and abandoned her.
At the film's climax, Andy, after returning home from Cowboy Camp, turns to his bed to find his toys welcoming him home. When he sees that among the toys are Jessie and Bullseye, Andy happily adds them into his collection, calling them "Bazooka Jane and her jet-propelled horse." Woody and Buzz both accept the fact that Andy will grow up, and even after he does, they agree to still be in each other's company.
Also, in Woody's nightmare, Andy comes back home early from Cowboy Camp and plays around with Woody, but he notices the rip in Woody's arm and decides he doesn't want to play with him anymore, dropping Woody through some cards and into a trash can, which he shuts the lid, trapping Woody inside. However, at the end of the film, when Andy finally returns home, he is the one who fixes Woody's arm, stating that Woody's arm may have come off completely if he hadn't decided to leave him home.
Toy Story 3
In Toy Story 3, several years after Toy Story 2, Andy is now 17 years old and is now heading to college as his slightly aged mother asks him what he will do with his toys. During his schooling days, he has participated in many athletic activities, as indicated by his trophies and certificates. Andy decides to take Woody to college and to put the rest of the toys in the attic. The toys are accidentally thrown out as garbage by Ms. Davis, and eventually wind up at Sunnyside Daycare. A small scene shows Andy looking for the missing toys, through the lost eye of Mrs. Potato Head. The toys make it back home, and Woody climbs into a box bound for college while the others climb into a box destined for the attic. While Andy gives his farewell to Molly and Buster, Woody writes on a sticky note, suggesting Andy to donate the box of toys to the little girl Bonnie instead. Andy sees his toys in the box, reads the note, and asks his mom if they should be donated, to which she leaves it to Andy's decision.
Andy then drives over to Bonnie's house to give her all of his toys and make her promise to take good care of them, since they have meant a lot to him. Then Bonnie peeks into the box to see Woody inside. She wants to have Woody, but Andy is initially reluctant to give his favorite toy away, but notices how much Bonnie loves Woody, just like he has during his childhood years, and hands Woody over as well, telling her to take special care of him.
He stays at Bonnie's house to play with his toys one last time. As he prepares to pull away from Bonnie's house, he turns to give his toys one last fond look, and thanks them for the fun and joy they have brought him. The toys then watch as Andy's car disappears down the street, and Woody says his final farewell to his old owner with his line, "So long, partner."