Extracting Stills from Video

Hi All

I know this isn't probably the best thing to do but what is the best way to extract stills from video. Would like then as high quality as possible from the video so screen grabbing not really an option.

A lot of people are saying us Photoshop Lightroom to do it but is there other decent free software or do I have to look for one of those long term trial codes for Photoshop ;-)

VLC player does it, might not be the best but it's free and easy