1. Clarkesworld Magazine - Pro's: quick turnaround of submissions, electronic submisssions, high prestige, award-winning semi-pro magazine, high pay rate (10 cents a word). Con's: extremely low acceptance rate, electronic-only publication, 8,000 word max story length.
2. Lightspeed Magazine - Pro's: extremely quick turnaround of submissions, electronic submissions, high prestige. Con's: extremely low acceptance rate, electronic-only publication, 7,500 word max story length.
3. Asimov's Science Fiction - Pro's: high prestige, electronic submissions, print and electronic publication, good exposure. Con's: low acceptance rate, slower turnaround times for submissions (around 40 days).
4. Analog Science Fiction and Fact - Pro's: high prestige, electronic submissions, print and electronic publication, excellent exposure, fairly quick turnaround of submissions. Con's: low acceptance rate, science fiction only.
5. The Magazine of Fantasy and Science Fiction - Pro's: good prestige, print and electronic publication, good exposure, fairly quick turnaround of submissions. Con's: postal submissions only, low acceptance rate.
I would generally classify these five markets as the primary professional markets. All things being equal, I would recommend submitting your story to these markets first - assuming that your writing is at a professional level, and that your story meets the specific requirements for each market.
Check out the submission guidelines for each of these markets for details on formatting and information on what type of stories they buy. Also, it is always a good idea to review a recent copy of any market you want to submit to, in order to get a feel for what they actually publish.
