Since a couple people already said Vash, I'll move onto a few other favorites.
Do I deny that nostalgia plays a part in my Inuyasha love? Nope. However I firmly believe it was a mostly pretty good series and I remain absolutely loyal to my sweet Kagome. I've liked a lot of anime chicks but I've only ever loved Kagome. She's always been my favorite character in the show and she will always be one of my favorite characters in anime.
From the ma Angel Sanctuary comes my favorite interpretation of Michael. He was just impossible to dislike with his spirited "screw you all!" attitude and a very relatable backstory and motivation.
Pegaus had the best motivation, the best deck and the best personality of any Yugioh villain. Een as he tortures our heroes you can't help but love the guy. With his Toon Monsters and silly attitude, he's the kind of guy you love to hate.
And then when you learn about why he's like this in the first place, it adds another dimension to his character. You learn all that silliness was just an act to cover up how deeply broken and depressed he is.