The SCIFICTION archive (http://www.scifi.com/scifiction/archive.html), of course, has all sorts of good stuff in it, old and new. A few picks:

'The Empire of Ice-Cream (http://www.scifi.com/scifiction/originals/originals_archive/ford4/)' by Jeffrey Ford

'The Screwfly Solution (http://www.scifi.com/scifiction/classics/classics_archive/sheldon/)' by Raccoona Sheldon

'The Women Men Don't See (http://www.scifi.com/scifiction/classics/classics_archive/tiptree2/)' by Tiptree vs 'What I Didn't See (http://www.scifi.com/scifiction/originals/originals_archive/fowler/)' by Karen Joy Fowler

'Over Yonder (http://www.scifi.com/scifiction/originals/originals_archive/shepard2/)' by Lucius Shepard

'The Heat Death of the Universe (http://www.scifi.com/scifiction/classics/classics_archive/zoline/)' by Pamela Zoline vs 'Anyway (http://www.scifi.com/scifiction/originals/originals_archive/rickert/index.html)' by M. Rickert

'Light of Other Days (http://www.scifi.com/scifiction/classics/classics_archive/shaw/)' by Bob Shaw

'When it Changed (http://www.scifi.com/scifiction/classics/classics_archive/russ/)' by Joanna Russ

'New Light on the Drake Equation (http://www.scifi.com/scifiction/originals/originals_archive/macleod/)' by Ian R Macleod