If I were using my real name I'd insist on cork. I'm not so I prefer screwtops. Example:
Pascal Jolivet Sancerre US$28.99 Wine.com
Pascal Jolivet Attitude US$18.79 Wine.com
They are essentially the same wine but Attitude has a screw top. Will I pay ten dollars for a cork. Nope! I have tried taste tests with my Sancerre-loving friends and they are unable to discern any difference. Screwtop for me!