It very much depends on what's your time scale.

Ideal
If you're not in a hurry to get a new job, then my recommendation would be to learn:

• SharePoint 2013 from an End-User/Super-User perspective
• ASP.NET MVC
• JavaScript (not just the language but also modern JS patterns)
• AngularJS
• SharePoint CSOM/REST Apis
• SharePoint App model

This will not help you answer the questions that many SharePoint shops will ask today, but this will prepare you to where SharePoint is heading and what these SharePoint shops will ask for in the future.

In a hurry
If you don't have the luxury of being able to do the right thing then you should learn the "old" way of developing for SharePoint as mentioned in the other answers