OK, so, here's my take on my top ten favorite characters. Not sure if I'm going to be putting them in any particular order, though the top five will probably reflect general precedence.
So, I think I'll start from one and work my way down, as that would be easier. Thinking of who to put first is definitely easier than who to put last.
1: Pterano. This spot goes to Pterano. He became my favorite character ever since I first saw the seventh movie, eleven years ago, and he's been my favorite ever since. He's certainly (in my opinion) the deepest of the sequel characters, and has left so many "what ifs" upon his departure. Plus I'm a sucker for the redemption character so... yeah.

There's just so many layers and potentional to him, and to me, complex characters are always my favorite.
2: Petrie. I like Petrie second because he was my favorite character from the original. I guess because personality wise, I'm a bit like him. Nervous, easily frustrated and wound a bit too tight, as well as occasionally suffering from a lack of self-confidence. But at the same time, Petrie shines when he really needs to, and is a very loyal friend, both things I've been known for in my personal life. So yeah, I guess because I can relate most to him, is the reason he's number two.
3: Chomper. I thought that he was a great edition to the franchise, and his nature of being a carnivore yet still being friends with the gang makes for an interesting take on sharpteeth. I think I like Chomper because he avoids the "stereotyping" that you sometimes get with other series, where one race is ALWAYS "bad" without question, and another race is ALWAYS "good". That's just so unrealistic, because unless you're a hive mind society, an individual is an individual, with the power to choose his or her own path in life, and Chomper does that quite well.
4: Littlefoot. I mean cone on, how can you NOT like Littlefoot? He really has a heart of gold, as the saying goes. Pure, courageous, but not without his flaws. He's also a bit of a tragic character as well, losing his direct family with the death of his mother and never knowing his father until much later, and experiences like that can make or break an individual at an early age. To rise above the crap that life throws at you and prevail, denotes to me at least a great inner strength, and so that's probably why Littlefoot is number four on my list. I guess I just admire someone who doesn't let themselves get crushed by their circumstances and stays strong throughout. Littlefoot's also a dreamer, and to me, that's never a bad thing, as I'm someone who's always tried to live my dreams.
5: Hyp. Yes, he made the top five. Surprising, I'm sure. Hyp is another sort of redemption character like Pterano, though not really to Pterano's extent. He was just a cool cat back in the day, and I always liked him. He's another character that leaves a lot of possibilities open, and I like that. The movie he was in may have been a bit overt in its message, but I thought the characters were well written, and showed development and growth, Hyp being one of them. A character that undergoes a significant change through the course of a story is something I rather like.
6: Rinkus. Always beware the minion who paints himself to be not what he seems. I like comparing Rinkus to someone like Atoq Navarro in Uncharted. He really just isn't what you expect until BAM. Guess what? Looks like your main antagonist is not really your main antagonist. He was being played this whole time by his subordinate, the guy you didn't really pay much attention to at first. Any villain that can come across this way is devious and tricky in my book, and wins kudos from me, as it shows they're complex and much more than they seem. Rinkus pulls it off far better than Sierra did, I think. Sierra was the brute force and the obviously discontented one. Rinkus however was the snake in the grass, biding his time and waiting for his right moment, not showing his hand until well into the game. He'd make one heck of a poker player, if poker of course existed in that time. XD I also see Rinkus as the guy who might surprise you in a game of a chess. He'd pull out unexpected moves and pass them off as "normal" with a simple shrug of his shoulders.
7: Ichy. Why, you ask? Good question. I guess for me, Ichy is just one of the more memorable villains of the series, and he stuck out at me from the earlier films. Unlike the host of sharpteeth you encounter, Ichy talks, and is a bird, which was a nice switch from the host of giant meat eaters you're normally fed in the series. He played off against Dil very well, and in a way they were really foils for each other. I liked the whole take on him being incapable of scrounging large meals without Dil, and Dil being powerless to obtain meals without Ichy's eyes. It was nice seeing the villains have flaws, instead of just the "Grrrr I'm going to eat you now" that I'd been seeing (not that I'm hating on the sharpteeth, I'm not). It made for a unique twist, and while they weren't as scary as that original sharptooth in the first movie, I still think they pulled it off. I guess I like Ichy over Dil for his biting sarcasm, as characters like that are quite fun to write. XD
8: Rainbow Faces. I know, I know. I'll be taking some flak for this one. But to me, they just didn't bother me as much as they could have. It's ambiguous as to what their relationship to each other is, and I liked that. It was really up to the viewer to decide, and their whole "guiding hand from a distance" approach I thought worked fairly well. They were the observers of the seventh movie, the ones who were present and could obviously do much more than they did, but willingly did not. I guess I liked their whole aura, and once again, they're another pretty big "what if".
9: Ducky. I guess I like her purity. She's very empathic, and I like empathic characters. Knowing what goes on in the heart of another is a tough gift to possess, but I think it's what makes her stand out and become memorable for me.
10: Rooter. Rooter gets number ten because out of all the scenes in the first movie, my memory of Rooter and Littlefoot sticks out clearly from when I was two years old in the theater. His advice has been so true. Pain fades with time, though of course, to add to what he said, one has to be willing to move on as well, and accept that your pain will fade. Overall, just a great, warmhearted character. My memory of that scene is something I hope I will never forget.