Write down a list of characters - real or fictional, book or movie, guy or gal or Gungan, - that you like, admire, or emulate. In fewer words - your favorite characters.
Done? Good. Now try to put them into categories by personality type. It doesn't have to be intricate, nor does it have to be very specific. Having just two is fine.
In fact, having just two would support our theory.
It shouldn't be too difficult for you to split your characters into two groups - not only is splitting things into halves easier, but also, as my friend Kelly G. and I have discovered, a character's like-ability to any particular person depends heavily on whether or not the character fits into one of these two groups.
Now it's a lot more fun - and more scientific - if you have your two groups set straight before I let you know what those groups are, as opposed to reading on ahead, figuring out those groups, and then going back to try to fit your characters into them. So, it's up to you what you want to do, but I aim to move on.
Category A is the "Be" category (confusing enough for you?), made up of the characters that you think you are, or want to be. You empathize with these characters, recognize traits in them that you have in yourself, and follow their storylines more closely because in some sense, they become you. Their like-ability stems from the fact that you empathize with them to some degree; you feel as though you can understand them, and thus, while you may or may not actually like them as people (to be discussed later), you can at the very least relate to them. You become interested in their lives, because those lives pertain to yours.
The phrase "or want to be" is not a limiting factor - it is rather an expanding one. Oftentimes, the people who we think we are similar to are not necessarily exactly the same as the people we want to be - they may often share similar traits, but let's face it - every once in a while, we find ourselves playing the villain. They're not who we want to be, but they are who we are. This does not mean that we are condemned forever to being the Moriartys, Draculas, and, Anakins of the world - it means that we recognize how our character traits, while strengthening us to a degree, can, if taken too far or without a dose of morality, lead to evil. Certainly, we can always try to change.
Some of the characters in your "Be" category are those catalysts for change - the people whom you would like to be. You look up to them, perhaps because they have traits you do not possess, but also because you can see yourself in the future, with help and a bit of luck, as them. They have, perhaps struggled with the same issues you have, have better mastery over their issues, and are stronger in areas where you are weak. They are you...but better.
Category B is the "Be With" category. It's very easy for fans to imagine themselves romantically involved with a character - fanfiction and deviantart, among others, have revealed just how often that happens. And as it so happens, unless you think using only your eyes and hands, your "Be With" category people will also tend to follow a personality pattern. And if you are worried that many of those in your Category B are of the wrong sex, that's okay - romance was just an example. These are the people whom you want to be around - whom you would choose as friends and partners, wingmen and bunkmates. They are the ones you can rely on to have your back, hold your secrets, and have some fun.
The "Be With" category may be very similar to your "Be" category, or it may be radically different, depending. Neither is good or bad - they simply are. Have some zen, and don't worry about it. The worrying comes in the next paragraph.
So now you have your two categories. What can you do with them, besides show them off to friends and look like a nerd? Chances are, if you've managed to separate them into categories, it means that these characters have some traits in common with the others in their group. So here's where it gets interesting - these common traits, along with some combination of the unique traits, can probably tell you a lot about yourself - what you see in yourself, what you desire for yourself, and what you look for in friends and relationships. You may find some very funny things - for instance, one of my friends discovered that while she herself was/wanted to be kind, helpful, and a generally cheery friend-type, she desired friends who were go-getter leader I-know-what-to-do types. You may find some more sobering things - I found many villains or alienated characters in my "Be" Category, people who were talented and clever, but often amoral or unfeeling concerning other people. You may find things you already knew, or perhaps discover an entirely new, unknown facet to yourself. And, of course, if you're doing this with friends, book/movie recommendations always turn up somewhere.