When is slowplaying correct?

There have been lots of posts recently, with titles like "Evaluate this slowplay", etc etc.

For you STTF'ers, what situations WOULD you slowplay? Hopefuly newer players can read this post and get away from FPS'ing every monster hand they make. Post theoretical hands, or whatever.

[bawcerelli]

how about the obvious ones like the flopped nut flush, and flopped top full house. sometimes i slowplay quads too. flopped royal flush i just check fold per SSHE.

Under normal circumstances I slow play a flopped nut flush, flopped BB special full house, flopped quads, and a top set on a very friendly board. Other than that I just feel like you are asking to be sucked out.