The "I just do magic, why or how isn't obvious and a mystery and let's leave it at that, I'm just magical" sorcerer.
So the most obvious way to get that from here that I can see is to be a wild sorcerer, and leave the actual origin of the powers a blank slate. The mechanics of a wild sorcerer would seem to support this, as it is unpredictable -- just the way not-completely-understsood access to powers beyond human comprehension should be!
No, the magic itself has always been something wonderful and sparks my imagination, but the image of the barbed guy in robes carrying a spellbook doesn't tickle my fancy. It just feels wrong, as some kind of nerdy power fantasy I just don't get. But it always was that way: magic=brains! No matter what, and despite the magic user/mage being labeled as the generic all purpose spellcaster, it always felt short to me, all of them were mandatory bookworms with the same basic backstory. The sorcerer was the answer, magic yes, no mandatory backstory double yes. All of the characters I always wanted to play were suddenly possible with a single class.
Yeah, I'm glad 3e introduced an alternate story for arcane magic, too (though I always think clerics get the short shrift in the look for alternate spellcasters -- like if someone can't cast Magic Missile they aren't even worth considering as a representation of a magical character, despite all the granted powers and inherent abilities). And I don't think 5e's backstory will be "mandatory" (basic is core, anything you add on after that is opt-in, so you want to take the sorcerer's mechanics and drop the story, and I believe that will be fine). So it looks like the 5e sorcerer isn't a bad fit so far...
But the problems were easily evident, the original sorcerer wasn't different enough form the wizard and had a lot of pointless limitations to prevent them to outshine wizards but that in practice limited the class versatility. And the fact that most people extended all of the flak they had with wizards to sorcerers meant that sorcerer players could never get nice things.
I dunno about all that, but it seems kind of irrelevant to this iteration, anyway.
And then in fourth edition, when they were focussing on making the sorcerers different enough, they picked the wrong thing to focus on and made it all about the bloodline, the bloodline, what before was a mystery and possible seed for plot hooks and character customization but that remained in the background when you didn't want it was no longer as subtle, instead it was hardcoded; it became all the class was about and in a bad way, typecasting the otherwise flexible and versatile class into an arcane barbarian that could only fry stuff in the process. Pathfinder went a similar way with the bloodlines, but the variety they offered left some room for character variety.
5E started pressing the right buttons, with metamagic and all that. But it went by the same mistakes of 4th edition.
I'm not sure I agree. The 4e sorcerers that I've seen haven't referenced bloodline at all, and 4e mechanics were so decoupled from flavor that it's hard to see much of any enforced fluff on the powers. Pathfinder would seem to be a different story, but I've got less experience there.
All I want is a spellcaster without scholarly baggage for whom magic feels like an extension of his/her being instead of a tool that is used and forgotten and without having to be punished by turning into a monster or a dangerous lunatic that puts the party at risk at any opportunity. Where's subtlety? where is elegance? where is beauty? I want a spellcaster that is as free to build things as to destroy them and not one that is only good for blasting.
I don't know how the 5e sorcerer can't fit this? Wild sorcerers don't have to be dangerous lunatics, they can easily be people just trying (and occasionally failing) to understand their dangerous powers, people haunted by an arcane curse, people with a strange something else about them that is a little uncontrolled and dangerous. It's not clear how transformative dragon sorcerers are going to be in the final release, either -- maybe they'll be fine, too, from a mechanical perspective.
It sounds like maybe you're looking for a mechanics-only spellcasting class that has no story attached, and that seems entirely possible within 5e's system, but I don't think "classes" are the place to find it. A 5e class is a story-based archetype from the looks of it, a group of powers with a role and meaning in the world, not just a naked mechanical skeleton. But I imagine that there will be the capacity to strip that out without much complication -- there's a unified spell progression that you can pretty much slap some a la carte class abilities onto and call it good, from the sounds of it.
