I traveled to Poland last year, with the benefit of exploring the country with locals. As a result, I visited some off-the-beaten-path places. Our home base was Poznań. I think without a guide, I would not have enjoyed it as much. There is great cuisine, shopping, theater, and sight-seeing. I didn't get to check out the nightlife, but there seems to be a lot going on.
A village I enjoyed very much is Chodzież. It has a slower pace, but is lovely. I had the best borscht I've ever tasted here. There are three lakes with trails, and a small town square. Not to be overlooked is the fine China factory. Here you can find absolutely beautiful dinnerware that would cost a fortune in other places. I plan to buy a full set next time I'm there. This is also where I went mushroom hunting, a tradition in Poland. Again, an experience I was able to have due to my hosts, and was very special.
I was in Inowrocław only briefly, but visited Tęźnia, which was unlike any spa-like area I've ever been.
One of my favorite towns was definitely Toruń. I loved the medieval feel, and the easy walkability. The Mikołaj Kopernik museum was not terribly interesting, but the gingerbread museum was fun. There's also an excellent hookah bar with very reasonable prices. But I found prices to be reasonable throughout my entire trip.
For my next trip our plan is to visit Zakopane. I'm very excited to see the architecture and glorious nature there.