.NET MVC is a great first step on the corporate dev path. You'll mostly work in cost center departments (see article). It'll pay pretty well for a day job, but you'll have limited market leverage as a cost center. You'll have to go where the .NET jobs are, and that's mostly big companies that treat IT as a necessary evil.

PHP is a great first step on the indie dev path. You'll work in smaller shops, pay can fluctuate wildly, but at least you'll be a profit center. It takes a bit more hustle to manage your career but you'll be better positioned to hang out your own shingle later if you're interested in doing so.

A few years of enterprise work can be a fine starting point for transition into more indie dev, but you'll have to be honest with yourself about the trajectory you're on from one year to the next.