If you're looking for a stack for the purpose of increasing hire-ability then you might consider looking up the jobs in the area you're trying to get hired, and seeing what comes up the most.
On the other hand, you could play around with multiple stacks, and see what you like. Then choose an area based on that.
Personally, if I was starting from scratch today I'd probably focus on the C# .Net Microsoft stack because there are a lot of jobs for that in my area.