Best places to live in New Jersey for 20 somethings?

So I'm absolutely hopeless at finding places to rent, and I figured this sub would have opinions either way on places to live in New Jersey.

We're 2-3 girls in our early twenties looking for a place (either apartment or house) somewhere in northern/central New Jersey. We've considered Morristown, Montclair, Hoboken, etc but we'd like to look more. As we're all buried under student loans, we'd like to keep it between $500-$700 a month per person (or as close to that as we can).

Are there any fun towns that we're overlooking? We'd like some sort of nightlife/things to do, access to the train is always nice, etc. Basically, a town that has something to do/fun things for 20 somethings and a demographic where we aren't the only young people at the bar. Where should I look?