I've always been the Dungeon Master.
From the moment I broke the cellophane wrapping on my Holmes Basic Set in December 1979, I was the default referee for all the many RPG adventures and campaigns in which my group of friends and I would participate. I certainly didn't mind. By temperament, I generally prefer being the referee and, when I am inspired, I think I can say, without too much hubris, that I keep the game entertaining. My forte, to the extent I have one, is the off-beat characterization of NPCs, both major and minor. My best creations are almost always eccentrics of one sort or another, individuals with personality tics or peculiar obsessions. Sometimes they're just background color and sometimes they're important elements of the unfolding story, but I think it's fair to say that, although many other details of my campaigns may be forgettable, my NPCs rarely are.
Consequently, I actually rarely get to play a character of my own. When I do, they often turn into somewhat toned down versions of my NPCs, oddities and all. Part of it, I suspect, is that I simply don't have a lot of experience with player characters, which are a very different beast than NPCs in my experience -- at least good ones are. By this I mean that a good NPC is often, by necessity, nothing more than a bundle of memorable quirks. That's how your players can keep them straight and not confuse one orc chieftain with another. PCs, on the other hand, need to be (generally) less caricatured while still being broad enough to admit change when random chance and other circumstances require it. That's why the best PCs I've encountered in recent years have all had both very thin backgrounds and "archetypal" personalities to start. Over time, of course, their backgrounds firmed up and their personalities developed subtleties, but, at the beginning, they often have less distinctiveness than NPCs.
All that aside, I did once have a character I played for some time, who, as it turns out, was my first character as well. Back in the ancient days, we played D&D almost every day we weren't in school and, while I was DM 90% of the time, that remaining 10% still represented untold hours of my wasted youth. So I was actually able to create a character and play him often enough for him to achieve the lofty level of 14 under the Advanced Dungeons & Dragons rules. Ironically, he was probably the second highest level character in our old campaign, because, unlike my friends, I never got bored with my character and created a new one every adventure. So, our campaign was littered, not just with the corpses of PCs who fell victim to untold hazards of the dungeons, but with literally dozens of characters between the levels of 4th and 7th levels, with the occasional one reaching in the 8th to 10th level range. Perhaps this is why I've got an almost congenital aversion to high-level play: we simply never managed to get characters to such lofty ranks.
My first character was, I am mildly embarrassed to report, named Sir James Calvert (his heraldic device looked like a thinly disguised version of the Maryland state flag). He was initially a Fighter, but I converted him into a Paladin once we got hold of the Players Handbook, because it better suited the concept of the character. He was basically a Knight of the Round Table of the Sir Galahad mold -- morally unimpeachable and a bit of a know-it-all. He traveled around with four henchmen who were themselves lower-level paladins that my friends would occasionally play. Unsurprisingly, we tended to battle demons and devils -- Sir James had a long-standing feud with Demogorgon and the various anti-paladins and death knights who served him -- and other exemplars of metaphysical evil. In time, Sir James acquired a +5 holy avenger, was granted a fiefdom, built a castle for himself, and adopted a young boy he'd rescued somewhere, whom he raised as his son. The son's name was Philip, if I recall, and I intended for him to become a ranger and take off into the wilds against Sir James's wishes, but I don't think I ever got around to that.
Looking back on him now, a lot of stuff I did with Sir James -- not least of which are his name and escutcheon -- were rather silly, but then I was barely 10 years-old and I had fun with it all, as did my friends. In the end, I guess that's all that really matters.