Preview is a pretty solid app. Unfortunately, I've never across anything remotely well done on any other platform.

Preview is good but I like skim a bit more. It has the note taking features and smooth zooming with trackpad pinch gestures. I cannot believe how fast it is too! Great app. One thing I wish it had though is the pdf editing commands that preview had to remove a page and concatenate different pdfs together.

Also: foxit reader is a great reader for window. Not quite as polished as skim but still the best reader I have come into contact with on the windows side of the fence.

Except when you have pdfs that use certain funny image-compression things that make it look fantastic in Acrobat and xpdf-based viewers; Preview does horribly on those. I agree in general about Preview, though. (It might be jpeg2000; I just know that when my dad scans a book, it looks good in acroread and xpdf, but in Preview it's very slow and pixelated.)

I guess you've never tried PDF-XChange or Sumatra PDF, then.

I like FoxitReader. It's non-free, but it does do facing pages continuous, which is great for reading on widescreen monitors.

Call me crazy, but acroread really worked pretty well for me.

I'm not sure what you mean by "pleasant" but xpdf gets the job done.

I like okular, the default KDE reader, a lot actually.