Career Advice for 6+ yrs Window Form Developer

I have around 6 years of experience in .Net Window Forms (Development and Maintenance) . My primary skills are C#,Vb.Net, SQL,ADO.Net. I want to grow my skillset as i am looking for a switch. But i am not sure which way to proceed should I shift to Front End or learn MVC, Angular Js etc. Please guide me which would be the most appropriate path to follow considering my experience of 6 yrs.