His collections of columns is most excellent.
An excellent collection of difficult hands
Daniel's Systems Page
A comprehensive collection of information about conventions.
. His monthly contests are difficult but excellent.
Bridgebum (Jeff Tang)
The "Food Asking Bids" are my idea of fun. Also in his excellent collection of articles is a reprint of the Grosvenor Gambit article from
Different. Half of the website is devoted to opening 4-card majors.
Another good, original, free bridge website.