(Ok, I'll have to be careful when I write this post or it will go on forever )

I absolutely admire Luke. I mean, if for any weird reason I'd be making a top five of fictional characters in the total of everything I've ever read and watched in my life, Luke would definitely be there. I can't even express how much he fascinates me, seriously.
Well, apart from repeating obvious things about him...I like how quickly he manages to accept the truth about Anakin...sorry, Vader being his father. That "NOOOO!" line has become something like a bad joke, but that was his first immediate reaction to getting this dreamlike image of his father that he was building up in his mind during his entire life shattered to pieces. But very shortly after this first shock passes, when he's at Millenium Falcon (don't know how much time exactly did it take Leia and Lando to find him, but it looks like it was not really long) and Vader "calls" him, Luke responds "father" and refers to him as father since that moment. I mean, he could have taken the attitude "you are no father to me" and it would be somewhat understandable, but he manages to accept his father the way he is. I find it really impressive.
Also I liked the moment in ROTJ when Luke and Vader talk on the bridge (or whatever bridge-like thing it was) and Luke turns his back to him after saying "I know there is good in you, the Emperor hasn't driven it from you fully". This gesture shows a non-verbal way of expressing trust I think. I mean, in this case when you turn your back to someone it means that you believe that this person will not "attack" you or do something bad to you, otherwise it's psychologically hard to turn your back to them. Ok I'll cut down on that because I can't really express what I'm trying to say
(eventually stating the obvious, I guess...)Furthermore, something that I respect profoundly about Luke is his ability to listen to what others say without abandoning his own principles. Don’t know how to say it, but there’s a kind of a firm “framework” about his whole character, if he believes something to be wrong he just won’t do it, like when he was told from basically both sides (I mean Yoda, Obi-Wan and Palpatine) to kill his father, but he refused. So, trying once again to formulate it, he has enough courage and self-confidence to do what his heart tells him even if no-one else supports the same view, and well, as the story shows, what he thinks is right. His character is strong but not oppressive. And Luke is the one who has the balance of mind and emotion in him – I mean, an absolute surrender to your emotions is no good, but the Jedi idea of completely rejecting all attachments doesn’t seem much more reasonable to me, and Luke doesn’t fall to any of the two extremes. So for me he is the character who shows real wisdom. (Hope that won't offend Yoda's fans, I'm not intending to say that Yoda's not wise, but something about him is kinda frustrating for me, so if I'd have to choose one character on this aspect I'd go for Luke)
Also, well maybe it's just me, but it seems to me that there's something reassuring about him. I was worried for him of course, but still every time he appears on the screen I get this kinda sub-conscious feeling that everything will be all right, he'll sort things out, there's no way he's gonna fail, something like this.
And well, as states the quote on that wallpaper I posted in Skywalkers thread, "faith does not spring for the miracle but the miracle from the faith" - thanks to his faith and courage, Luke was able to induce the miracle.

And I love his smile No, seriously, there's something about his appearance that reflects his inner light. I think the actor is just perfect for the part. I've heard that there were some movies where Mark Hamill played bad guys, but I don't think I'll be able to watch those

I don't have a lot of Luke fanarts so I hope photos will do.
Click on the previews to get the actual size.

There does seem to be an inherent goodness and almost innocence to Luke. You completely believe him as a pure hearted hero.

That is true. No other hero will top Luke.