I'm just going to list the characters who I adore, but in no specific order 83 *will probably end up ranting*
Haku [Naruto] - Since his first appearance, I just adored him. The way he presents himself is so polite and kind, even to those who're his enemies. Due to his devotion to Zabuza, he puts forth a 'ruthless' facade, but it's completely against his nature and it shows. I also think he, as a character, was used very well as a plot point. His words get reflected on multiple times, even after his arch is over. So all in all, I think he's an amazing character, definitely my favorite in all of Naruto.
Harada Risa [DNAngel] - I LOVE RISA. I love love love Risa. I can't really put it into words well, but I think she is the pinnacle of character development in DNAngel. Everything about her changes hugely, even though she remains the same person in essence. Spoiled and materialistic she may be, but that's only at the beginning. Not to mention she has unlimited devotion to those she loves, no matter how she may behave. ♥♥
Allan Walker [D.Gray-man] - *sigh* Allan is just precious. I can't get over how sweet and polite he is, and then on the turn of dime he becomes fierce and passionate. I haven't been able to finish the entire series yet, but he's one of the most amazing MCs I've ever seen. I love how he isn't hard-headed in the slightest.
Sora [Kingdom Hearts] - Eh, I'm listing Sora since KH was published into a manga, so yeah. Sora is my absolute favorite character of all time ever. He's just amazing, everything about him! He's endlessly devoted, determined, and more than anything, he's willing to throw away everything in order to save the people he loves. He has no qualms about helping someone he barely knows, and will go out of his way to do even the smallest favor for someone.
Riku [Kingdom Hearts] - Basically, he and Sora are completely tied in my book for #1 favorite character ever. My favorite thing about Riku is his role in the KH plot: in the first game/manga series, he's shown making decisions based on jealous feelings and lust for power. In the second game all the decisions he's made are to correct the mistakes he made, and he's become much kinder in the process. Just like Sora, he's willing to give his life for the people he loves. On a smaller scale he was willing to do that in the first game, but he definitely grew as a character in the second game.
Edward Elric [Fullmetal Alchemist] - KDJSHKASDHKAJDHAKDJH ♥♥♥ I LOVE ED. His personal experiences that are all scattered throughout the story and his utter respect for human life make FMA FMA, absolute and completely. Absolutely one of the best characters ever animated or printed in ink, no questions about it. I love his personality as well, how deep he is while remaining child-like. I can't go into a complete description about how much I love Ed, it might take up the whole page ;A;
Alphonse Elric [Fullmetal Alchemist] - Everything Ed is, and yet amazingly sweet. His burdens are so human, and they just strike a chord deep down every time ;A; I swear, just looking at him makes me want to cry. </3
Rock Lee [Naruto] - I remembered who I was forgetting! Lee is definitely on top of my list of favorite anime characters. The most obvious reason is because the boy is (before you get used to his face) quite ugly, but has one of THE most respectable, wonderful personalities I've ever seen. He's so honorable, kind, and honest. To be perfectly blunt, I prefer him over most characters, however good looking or unpleasant they may be. Rock Lee pwns all bad boys :>
Nara Shikamaru [Naruto] - I have no idea how Shikamaru became practically my favorite male Naruto character, but he did (he might've if it weren't for Haku :B). But his personality is so appealing to me, I dunno.
Yamanaka Ino [Naruto] - She's so awful and unpleasant D: I love her to death. plus InoShika be my OTP *cow'd*
Deidara [Naruto] - I.. love.. Deidara. He's hilarious and funny and amazing and wonderful and his attitude is horrible. ♥
Tobi [Naruto] - Same reasons as Deidara 'cept with a good attitude :3
Itachi [Naruto] - .. I .. have no reason to love Itachi except that I do. And because I believe he will die nobly. *wishful thinking*
Sasuke & Sakura [Naruto] - I don't want to rant anymore, but.. I love both of them so much and so equally, I can't not list them. Both of them are dynamic in their own way, and I can't even begin to list all the reasons I find them to be amazing characters. I shall leave it at that.
Tsunade [Naruto] - Tsunade is AMAZING. Her personality and her past and her power and her face = all amazing. Tsunade = JUST AMAZING.
Naruto [Naruto] - Uhh. well.. the series is named after him for a reason :B <33
Honey-senpai/Haninozuka Mitsukuni [Ouran High School Host Club] - He's so cute *v* So so so cute..
Mori-senpai/Morinozuka Takashi [Ouran High School Host Club] - He's handsome and tall and quiet, completely devoted to someone who's 1/3rd height, and he has animal instincts. Mori = ♥♥
Roxas, Demyx, Namine & Axel [Kingdom Hearts] - I love these guys for infinite reasons, and probably as much as Sora and Riku. But I didn't want to spam the page with fangirling, so I won't.
Kanda Yuu [D.Gray-man]
Erza Scarlet [Fairy Tail]
Natsu Dragonil [Fairy Tail]
Gray Fullbuster [Fairy Tail] - <3333333 *fangirl*
Hitsugaya Toushirou [Bleach]
Kurosaki Ichigo [Bleach]
Ulquiorra [Bleach]
Kuchiki Byakuya [Bleach]
Kuchiki Rukia [Bleach]
Bakura Ryou [YuGiOh] - Almost five years later, and Ryou is still my favorite YuGiOh character -_-; In the manga and the anime, he was just precious and sweet. He didn't deserve his end (in the anime, I never finished the manga), he absolutely didn't.
EDIT:
Kairi [Kingdom Hearts] - everything mentioned by Natti (below post) :3 I used to hate her, but I can't say I really do anymore. She's sweet, brave, and pretty to top it all off. :0
Tifa Lockhart [FFVII] - Tifa = the best FF girl ever invented. Ever. I'll never believe otherwise.
BIG POST, I KNOW. And yet.. I feel like I left someone out..