I enjoyed the long running "Asimov's Science Fiction" and "Analog Science Fiction and Fact" the most, but the newer "Clarkesworld" was also quite good. If you'd prefer a large tome, go for "The Year's Best Science Fiction" by Gardner Dozois. Ooh, and can't forget http://escapepod.org/
The Year's Best Science Fiction and really all the collections edited by Gardner Dozois are fantastic. Sadly he died but there are years and years and years of great selections.
Electric Literature
Also Ted Chiang (Your Life and Other Stories, Exhalation, ...)