I generally roleplay third person, but not really from a set of archetypes or anything like that. And not modelled after existing characters.
The very first characters I played when I started roleplaying games, I just played the game without really thinking about it. They weren't self inserts or defined alternate characters. But I would take whatever the game gave me, find an interesting image of a character and the concept that stirred, then inhabit that character, so they ended up taking on some of my traits. Then when I replayed games, I would conceptualize something very different from what the first character became, and work toward as divergent a story as I could. I never saw totally upright, in the lines characters or simply malicious characters as all that compelling, so I've always stayed away from the static extremes. I chafe against game systems that try to force me into only certain molds.
But it was more just this organic transition from my artistic and creative tendencies. I've been creating characters in my head all my life, and I've always been captivated by visual storytelling media, whether that's movies or comics or those grand epics I used to play out with dozens of figurines as a young kid. And I enjoy reading, but I visualize everything. I've been drawing as long as I remember, and building stories (or generally situations, states in which they exist originally) in my head for all those characters. Then I started writing and building interconnections and plot dynamics with more intent. So gaming has become more and more of a creative exercise alongside as I've gone on, but it's still an evolution of that approach. I try to roleplay a new, unique character every time if a game allows for it, but I start with just letting it come to me, or in DA's case, by letting the story so far influence who my character is going to be. I try to have only a rough idea of who my character is and where I want to take them at first. Then I attempt to find the most interesting character arc and conflicts for that character and build from there with what the game gives me. The most interesting playthroughs are always those that develope strong character arcs. Video games are really a collaborative medium; I don't try to force a concept on a game like a square peg in a round hole. In some ways, it's also like drawing a sketch, just constructing an experience from inspiration, and I enjoy that process.
That's why I love the first game's origins so much. There's just so much depth I could layer on from that system.