The Girl on the Train has an intriguing premise but fails to build up any tension for the first half and you're not exactly rooting for anyone. It's only worth watching for Emily Blunt's searing performance as Rachel.
The odd cool idea and good supporting cast couldn't elevate The Last Witch Hunter to be particularly interesting and I have no desire to sit through it ever again. It does have a few entertaining moments though so maybe rent it.
Krampus mixes comedy and horror with mixed results but despite its flaws it looks fantastic, the cast are all entertaining and it's one of the crazier Christmas themed movies of recent years. You need to watch it more than once to appreciate it.