This may sound odd, cosidering that I'm a male and all, but my personality matches Ali's the closest. Growing up, I never did much with those I felt were different than me. Now don't think I was conceited. What I meant was, since I was always a little abnormal, I tried to stick with my own kind, those that thought in a similar way. Ali was the same way as a child. And although this story would fit perfectly if a said something like, "But I met someone like me and he made me realize that it's good to have all kinds of friends," I said we were similar, not I am her other worldy double. Ah well. My version is much more simple and actually typical and boring. I simply didn't want to be classified as a type anymore and started socializing with different types of people.
If you'll think back to Ali from The Brave Longneck Scheme, I still have a connection. Now I move a lot like Ali, meeting new people. Now we can see in that episode, that Ali makes a new friend, Rhett, and tries to please him by doing pretty much whatever he said. I am the same way. Not was, am. To this day, when I meet someone, I try to be a "good friend" and try to make him or her happy, completely neglected my own well being, just like Ali did. Now I'm not saying that everyone I meet takes advantage of me, but most people I meet want things a certain way, and I simply aim to please.
Now, if I could meet any character from any story about The Land Before Time, I would definately like to get to know my all time favorite character, which is definately Rita the longneck from Sharptooth Valley. Her personality is very similar to Littlefoot's: oversized heart, caring for friends absolutely, very motherly as proven with Chomper in the sense that Littlefoot was fatherly to him. She apparently is difficult to anger and she is very trusting. She leads the group at times and has yet to be mean to anyone. The main difference is that since Littlefoot is a boy, he approaches life in a masculine way, while Rita is definately feminine; to call her a tomboy would be as inaccurate as statements go. So that's it. I have always liked Littlefoots pure personality and I have always liked girls. Now I can have both wrapped up in one.
Now if this thread was specifically limited to characters from the films and/or episodes, my apologies, I wasn't sure so I just answered with complete honesty. But if an "on screen" character is what this is about, then my second choice is Chomper. He would make the perfect little brother, or perhaps "mud brother." He has the ability to make those around him laugh with out actually trying. (One random example would be from The Meadow of Jumping Waters when everyone said a cloud looked like he was eating sweet bubbles. Everyone knew he doesn't eat them, but he announces that so matter of factly as if nobody knew, that every thought it was funny and burst into laughter.) He is a bit immature, so we would actually get along perfectly, hehe. Chomper is innocent, friendly, and yet will stand up for what he believes in. That's why it'd be great to meet someone like him.