If you've been following my compulsive numerical analysis of things like honorable mentions in various Year's Best anthologies, then you might be forgiven for expecting me to endorse a similarly quantitative guideline of a "good" market.
I won't, though. My convoluted number crunching is a way of orienting myself and beginning my research of markets; but I frequently -- usually! -- submit to several markets that are nowhere near the top of that hierarchy.
It seems to me that there is only one useful criterion in deciding whether to submit to a certain market: Does that market publish stories you admire? Full stop.
There are markets that were only names on Duotrope to me until I bought and read an issue -- and then became a devoted booster and fanboy, badly wanting to be published in that mag just so that I could be counted among the wonderful writers I found there.
I suppose that pay rates and audience size are also valid criteria, but nobody expects to make a living at 5 cents/word, and the audiences for novels are orders of magnitude bigger than for short stories. I want to be paid something, yes, but mostly in order to know that somebody liked my work that much. A miniscule payment that is coming out of the editor's own pocket is an honor, or so I think of it. I want an audience, sure, but that's because I want to reach other people's hearts & minds. Small audiences are a blessing when they read the work carefully and tell you how much it meant to them. Once upon a time, when I was writing for a tiny audience, zero pay and possibly negative prestige, a reader sent me an e-mail saying that one of my stories had helped her through a difficult time in her life. Seems to me that that's the best thing a writer can hope for.
And I'm proud of all my publications, even the non-paying ones, and consequently I list nearly all the markets in the cover letters. If a venue wasn't ashamed to list me among its authors, then I'm certainly not ashamed to list it among my achievements.