Mainly street level, but I like reading high level teams. Right now I'm reading New Avengers and Guardians of the Galaxy, along with Deadpool, hawkeye, soon to be daredevil.. I think I like seeing the personal thoughts and stuff in a solo street level series, but also the team dynamic of high level teams.
What would be an example of a mid-level character?
I voted street level, more relateable and fun to read. After that my favourites would be high level, then cosmic level.
EDIT: after street level i'd vote mid-level then high level, then cosmic level. I think sky father level would be on a higher level then cosmic level though.
I mostly like characters based on design, personality, and story. Powers is a secondary concern of mine, but I do tend to prefer characters that are between street and mid level in power, since not only are they more realistic (even in a pseudo-science medium), but that their fights are more interesting. You see Superman in a fight and you know he's going to win, there's not much tension. Not only that, but you generally have to make characters that are as or more powerful than Superman, to which point they often get defeated in anti-climatic ways and then get sweeped under the rug by writers because they are too powerful. With weaker characters, you can still see very impressive displays of power while still feeling like they are vulnerable and may not succeed, and their villains can have more creative abilities to make the fights more interesting than just a boxing match.