Thinking about this subject, I've come to realize that all 5 of the characters relate to me and seem to be part of my daily life in some way or another. This is something that I'll discuss as I go over my opinions of these characters.
Now...where was I? Oh yes!
1.
Petrie: A no-brainer. I've probably said a million times why I love this little guy, but I'll take the time to say so again. Petrie has always been my favorite ever since I rediscovered LBT three years ago (ironically, he and Spike were the characters I had totally forgotten about before then). Perhaps it's the voice that caught my attention (pick one), or the fact that he's just all-out funny to me. Nevertheless, he's the cutest character I've come across in my book. Sure, he has his fears and flaws, but most of them won't stop me from liking him, especially because I have many of his fears as well, like not always willing to try out new things, often relying on others for help when in need, idolizing others only to find out they are not so worthy of being idolized, etc., etc. Despite this, he is very loyal, good-natured, innocent, and has a heart of gold, all of which are things I am known for in my life.

This makes him the most relatable character to me.

2.
Ducky: I love Ducky very much, I do, I do! I'm not sure if I could say she's just as cute as Petrie, but...oh what the heck, she is!

I love her own innocence and how she is so optimistic about herself and the world around her. Not to mention, her relationships with Petrie and Spike make her all the more adorable. Her naivety (which was constant throughout my childhood) is also something for me to chuckle at. The only thing I have to nitpick about Ducky is her frequent role as the so-called "damsel in distress", with her finding herself in danger several times and needing to have someone else come and rescue her. I often wish the role could be turned around somewhat and perhaps she could save someone else's life for a change(Cera about to fall off a cliff, Petrie falls into water and starts drowning, etc.). Despite this, she is a wonderful character to have around, yep yep yep!

3.
Littlefoot: Ahh, the main hero of the series. I guess I love the fact that Littlefoot is up to do anything his guts tell him to. When no one else is willing to do something that is problematic, Littlefoot is always the first one to step up to a challenge. Having also put his past troubles and traumas behind him (something that I have done as well), what with the death of his mother and the struggles to find the Great Valley, it is clear that Littlefoot is the strongest character in the franchise, for without him, I'm pretty sure the franchise wouldn't have even existed, or if so, be half as successful. If only he didn't hog up so much screentime...
4.
Spike: Always a fun character to have around, Spike, to me, represents the person who is always willing to listen to anyone and does not judge what others say. Perhaps the fact that he is mostly mute is the cause of the case, though nevertheless, he expresses his personality well through his simple actions. His bond with Ducky is something to adore. Although some people might say that Spike's muteness is a disability of sorts, I would completely disagree. I am autistic, yes, but I am quite thankful that I am not mute, which unfortunately is what a lot of autistic kids and adults are. Perhaps those people who watch LBT can relate to Spike more than any of the other characters.

Anyways, Spike is simply the character we'd all feel lonely without. In addition, we both have just about the same appetites.
And lastly...
5.
Cera: I've always been iffy about Cera. She has quite a soft side, yes, but behind that is a prideful, gruff exterior that has always irked me to no end. Obviously, this behavior is quite understandable, as her father (someone I certainly wouldn't want for a father of my own

) is the cause of her biased statements and insults she would throw at Littlefoot and the others. While this behavior has softened quite a bit since then, it still shows often to a lesser extent, though it can be humorous and it comes in handy at times.

That being said, she is also quite tough to figure out; she could often turn back on a friend after an argument, and yet save said friend from sudden perils that he/she may fall into (7 anyone?). I like how Cera slowly but surely learns from her mistakes (also relatable to me), even though she hates to admit it.

Without her, I suppose the franchise would just simply be a bore, but nevertheless, she is simply a character that I have a hard time figuring out.
And that's all. If I were to include Ruby and Chomper on the list, Ruby would be after Ducky (she's strange, yes, but I like her personality, her big sister attitude, and of course the way she talks, the way she talks of course

) and Chomper would be either before or after Littlefoot (only unsure because he seems to be more relatable to me; innocent, naÔve, and judged often only because of his species).
Whew, this was quite a lot of thought for me to put into. Now if you'll excuse me, I shall go and get myself a huge bottle of water. Oh wait, I don't think we have any of those...

Oh well.