I've always been an equal-opportunist when it comes to magic. Something that's stuck with me from 7th Sea is the notion that in a world where people are born with the ability to use magical powers the formation of a permanent aristocracy is not only borne out by the abilities of that aristocracy but actually justified. In a sense, magic users are truly better than other people.
Now of course, this doesn't hold if the skill is one that ignores the barriers of class or race. It would almost be a requirement for the ability to do magic to pass along hereditary lines for such a stratified nobility to form. For whatever reason I balked at the idea, and have strongly been in favor of a magic that was knowable by anyone who dedicated enough time and energy to studying it (and who possessed at least an average amount of human intelligence, of course). Still, there are races in the 10th Age that not only do not possesses a culture of magic but have no magical aptitude at all (dwarves and halflings come to mind).
But what about a world where magic is an ability that takes shape in a random, unidentifiable pattern amongst the population? This still singles out some people as "exceptional," which is something that I reject on a gut level. I'm not certain why—perhaps because of my ingrained belief that "exceptional" people are simply those with the drive to improve, that no matter the baseline of skill any given person starts with, it is dwarfed in importance by the effort put into developing that skill.
I can't think of anyone I know that's ever run a game where the option presented itself who has chosen to enforce magic as a special marker, something that makes you apart from the rest of the population. And yet, one of my favorite fantasy series (R. Scott Bakker's Second Apocalypse) features magi who are granted power in exactly this manner. They simply exhibit the skill when they are young and then are either snatched up by the powerful Schools.
I'd love to hear from you guys about your preferences. What kind of magics do you allow (if you run a game with magic, of course) and what kind do you prefer? Is there something inherently alluring about the prospect of being given (by random lot) the ability to control the very fabric of the universe? It seems to be a common trope in fantasy books that sorcery is an inborn power... so where do you stand?