There's now 21 Zane Grey novels available on Feedbooks:
http://www.feedbooks.com/discover/view_author/255
The 3 most popular books are:
1) The Call Of The Canyon:
http://www.feedbooks.com/discover/view_book/1815
2) The Last Of The Plainsmen:
http://www.feedbooks.com/discover/view_book/1820
3) The Young Lion Hunter:
http://www.feedbooks.com/discover/view_book/1868
The top western book on Feedbooks remain the same, A Texas Matchmaker from Andy Adams:
http://www.feedbooks.com/discover/view_book/911