I enjoyed this game for the GameBoy Advance:
The Land Before Time - GBA (also known as "The Land Before Time Collection")

It's a nice side scrolling game with outstanding music, many levels and good graphics.
More information here
There was another game for the GBA with the name "Land Before Time: Into the Mysterious Beyond", but I disliked it because of the bad game control.
Weird. From what I've seen of the other LBT videogames, they kinda sucked.
But I can totally see them as a side-scroller.
As for mine, I'd think it's games based on the expanded universe of the film that work best, rather than a videogame based exclusively on the film. Examples include:
LOTR, Battle for Middle Earth
Star Wars Battlefront 1 and 2