I've got the Ciri-witcheress/Geralt alone ending. After watching all the different endings, I still consider that the best possible ending for me, despite the obvious appealing of a happy life in couple.
I've thought a lot about Triss/Yen/alone outcome but for me the simplistic "and they lived happily ever after" doens't fit well with Geralt character, a character always struggling between witcher neutrality and apathy and his kindness and emotions. In any case a person who doesn’t fit well in the lazy husband role. Furthermore, I candidly loved both in the game: Triss because she cares so much about the witcher, she is very sincere in this game and I find her timid crush on Geralt heartmelting and Yen because she is like a wife for Geralt and all the love she shows for Ciri is underwhelming. In addition, I think that Geralt HIMSELF has loved and still love them both in a sort of different way, like Triss suggested before the “threesome incident”. I know that from books it’s clear without doubts the different scale of values between Triss and Yen but the games are set after the books and they evolved in their way and if ppl want to consider them canon, then the “books reason” is not a valid statement anymore. If ppl didn’t consider games canon, than this entire discussion is pointless.
So, I still consider this ending the best ending for him and for Ciri, both living how they always wanted to live, free and wild like a lone wolf and a swallow. In addition, I think that lots of ppl misunderstood the "alone" ending. In my opinion it does not exclude that Geralt will eventually have further contacts and involvements with Triss or Yen, and this without being forced to live for feasts that he actually doesn’t like so much (Triss) or without the need of banishing himself away from the world to make little talks with Yen.