Oh wow. This is a SUPER-HARD question, because, uh, I have 400+ characters to choose from. ;-_- I'm kind of addicted to creating characters. Like, I've done the 100 Characters Meme, and couldn't even fit HALF of my characters in there.
But here goes!
I really, truly like Masahiro's design. It might sometimes be a pain to draw with all the details and stuff, but I like how it's not just some clothes - it's his personality coming through in the costume design. Also, fairly neutral colours = looks good in 99% of lighting conditions. Also, it's a nice challenge to design around the fact that he only has one hand, and chooses to hide the other in his sleeve.
I've got some other designs in Grassblades that I really like, but I can't show them because SPOILERS and all.
So moving on to other fictional universes....
Scifi-verse!
This is Vesto! She's been kicking around in my head for a while, but I finally sat down and did a proper design for her a couple of years ago, when I decided to pitch a comic for an anthology (which I was unfortunately rejected for - but hey, the comic got published somewhere else!). Vesto is a space-adventurer who does a lot of landing on strange asteroids, exploring forgotten planets and climbing on stuff, so I went with both space-suit and sensible-shorts-with-big-pockets elements in her design. The blue circles on her face are implants that allow her to turn her blue visor on and off,
And here's her antagonist - Niyorah Tri-Eyes, the scrapdealer/pirate. Because who DOESN'T like space-pirates with rusty metal prostethics and synthetic third eyes? XD
There's a bunch of other characters in the same universe - a ship's AI that wanders about in a robot body, a salamander-based alien fellow who works as a pilot but only because he got kicked out of a guild for exo-linguists, Vesto's brother who is an interstellar diplomat, Niyorah's sidekick who is a gun-slinging, stone-faced lady of an alien species very vaguely based on a lemur, etc.
.... Honestly, I have more ideas than I know what to do with.