There are a few movies on Netflix streaming right now that I really think you should watch while you have the chance! Here are a few recommendations of what I think you should watch this Thursday night while you still can:
30 Rock (Seasons 2 and 3)
Friday the 13th (the original, and 2, 3, 4, 5, and 6)
Lost (Seasons 1, 2, 3 and 4)
Office, The (Seasons 3 and 4)
Star Trek II
Star Trek III
Many of these movies will come back, as there is an "ebb and flow" to what's available (due to licensing issues) via the Watch Instantly service. Of course, you can always get a mailed DVD to your door (and these types of movies usually come pretty quickly anyway). Either way, have no fear, because you'll be able to watch it sooner or later.