A lot of people like to design their characters as "builds", meaning that the mechanical elements are prioritized, and put together according to what will be the most powerful, or the most survivable, or the best at accomplishing certain specific tasks. For these players, the mechanical FUNCTION of their character is the most important thing, taking primacy over any other considerations. Whether or not they "like" gnomes is irrelevant - if gnomes have the best bonus to X, then they're picking gnome. For these players, there is definitely such a thing as a "best" character build, and often times, it makes no sense to them at all why anyone would choose mechanically subpar character options.
On the other hand, there are the people who focus on the thematic or narrative elements of their characters above all else. They don't concern themselves much with whether or not the build they put together is powerful or "best" or most optimal mechanically, they just want the STORY of their character to be cool, unique, or exploring certain themes that they are interested in. They will choose a race with no bonuses their their class' main stats, just because they like the IDEA of being a half-orc wizard, or whatever.
Sometimes the first group are called "powergamers" and sometimes the second group are called "roleplayers", but those labels do not always apply.
Now, you may be saying, "I do a mix of both of these things!" And of course, the two groups described above make a Venn diagram with plenty of overlapping space, so there are lots of players who are somewhere in the middle. But I've found that most RPG players tend to lean, at least a little bit, toward one side or the other. I, for one, am definitely a mix of both, and sometimes prioritize build over narrative theme, and sometimes vice versa.
I like to make characters who are FAIRLY strong in their mechanical role, but which also have role-playing elements that appeal to me and that make for a good story. I won't always use the most powerful thing (class, spell, feat, equipment, whatever), if I don't feel like that thing fits the character concept that I have in my head. But I do try to choose things that complement each other, most of the time.
What about you?
Hard to answer this one clearly; my favourite type of character for many years has been and remained a well-built paladin, and it is both the build and idea; from my point of view, the mortal epitome of divine power just should be given an edge above most of the folks around him. Yes, it is a privilege, and the duty both. The one who has received a lot should do his best to uphold his inner ideals, in word and deed. And if you can do what's right - more the power to you, even if others view you as a munchkin.
For other characters, I never go with a perfectionist mind, because sometimes I would prefer being "just one of the friends" for a camaraderie spirit.
