I am far from an expert, and just beginning down this wonderful road of cheese exploration myself, but here are some of my discoveries:

The aforementioned Norwegian gjetost is wonderful. It tasted to me like a rich, thick peanut butter. I had a slice on the smorgasbord at EPCOT

When I was in Ireland I sampled a wonderful local cheese in County Clare made with seaweed, a creamy cheese with a very strong flavor. The seaweed was in veins within the cheese, and made it spicy.

I've gotten a cheese called Drunken Goat - not for the wimpy, very strong flavor. It is goat's cheese cured in port, and has veins of purple running through it - got it at my local Fresh Market (upscale grocery store)

Another I like is Stilton, with various fruit flavors in it, or port.