Polarising filter

[Richiex1]

I've just purchased a D7000 and want to get a circular polarising filter for the 18-105 kit lens. Looking on Amazon there seems to be a very large price differential even between the same brands. a 67mm can be from £19 to £90 +
What makes a good one and how do you know?
Hope someone can help and sorry if this is a daft question, if you dont ask you'll never know.....!

 

[gad-westy]

Just to get the ball rolling, I hear good things about B + W and Hoya CPL's.

I get the impression that you get what you pay for with CPL's. I had a cheap Jessops one and it seemed to dramatically soften my images.

 

[a1ex2001]

Marumi DHG Super - great value for money and has done really well in round ups.