I still haven't read Y, so I can't make any comparisons.
But I loved the end of Preacher. For all the weirdness and over-the-top shockery that characterized that series (and don't get me wrong--I love Ennis' outrageousness), at the core of it all are the very human, very fully-realized characters and their journeys, and I was very satisfied with how it played out. Jesse and Tulip got to ride off into the sunset together (and how else could they possibly end up), Cassidy got a second chance at life and redemption, and the Saint did what he set out to do and finally got a chance to be at rest.
I think Cass' ending affected me the most, though. He was such a loveable bastard that I truly hated to learn all the depths to which he'd sunk, and the fact that he got the chance to grow up and live life as a man in the end really made me happy. A great redemption story.
--g