Stringer Bell is a character who tried to rise above the streets and that's what I find appealing. I'm sure that's what any black fan of The Wire finds appealing, and for that reason Namond, D'Angelo, Bubbles, Cutty and String are my favorite characters in the show. He started in the streets and wanted any way to get legitimate as possible in a group of guys who just wanted to do straight gang banging. He had big dreams, unrealistic ones even, but what makes Stringer Bell an appealing character was how poetic his story is. String was too smart for the streets (what he wanted to escape from), but too dumb to be a CEO businessman (what he wanted to be) - if getting conned by Clay Davis is to be an example, then again, Clay fucks everyone.

He ends up dying through his own means and business philosophy. If he weren't raised in the ghetto, String could have been a successful man in a legitimate business. Maybe not a CEO, but he had the skills and know how to be legit and nowhere involved in that gangsta bullshit.
Honestly, String should have just left B-more and went to NYC, forget all that gangsta shit, and set himself up a small business.
I found it eerie how Marlo is given what String wanted, and throws it away, and lurks back to a random corner to stare death in the face. For me Stringer represents an attempt to rise above the corner and the ghetto and you can't do that. Either you leave or you're in it for good.