[Update: Apex Magazine's guidelines have changed] I recently posted a reference to Apex Publications and their 'Dark Faith 2' anthology, but they also have a regular magazine that I'd thought I'd highlight:
Apex Magazine is a monthly science fiction, fantasy, and horror magazine featuring original, mind-bending short fiction from many of the top pros of the field.
They are a SFWA-certified professional market and accept work up to
7,500 5,000 words, paying 5 cents per word, so it'll be a tough/prestigious nut to crack if you choose to submit. Check out submission guidelines here: http://apex-magazine.com/submission-guidelines/