I'm just north of Philly in a spot that makes it easy to catch a train and see shows in NY without much advance planning.
Geographically, it's a great location for theater with good access to NY to the north of Philly and Baltimore and DC to the south, which is a drive I'm used to since I have good friends who live in Maryland. Add in occasional tour stops like Hershey or Wilmington, and there are plenty of opportunities for theater day trips.
No one from Minnesota yet, eh? Well, I'm in the Twin Cities - a southwest suburb of Minneapolis. My first trip to NYC was last December, and I've already been back. I'm sure I'll go at least 1x/year.