The premise doesn't do it much justice, as it sounds dull. A travelling merchant and a wolf deity (A goddess of the harvest) travelling up north, engaging in serious business and economics at a slow-pace. As boring as it may sound, it turns the economics into something compelling and interesting, or at least I saw it that way. This definitely depends on what you find fun, as even though it explains the economics and logic of coinage and currency, this isn't everybody's cup of tea.
Economics is half of the anime while the other half is the banter and dialogue between Horo and Lawrence. Fortunately, it's just as good if not better than the economics aspect. It feels natural and real while remaining fun and serious when needed. And even with other characters it's spot on. How they explain plans and schemes without making it feel like an explanation for the viewer or a lecture. They incorporate it into their world and we just listen to it through them.
There's a second season and unfortunately no third so there's no real conclusion to the tale but the arcs are brilliant, fun and packed with the joys of money and goods.
Right off the bat, you hear the beautiful OP. It is a work of art and one of the best I've heard. You can't talk about Spice and Wolf without the OP. And the music all-around fits the setting. It isn't out of place nor intrusive but it remains in the background adding atmosphere to it. The VO's are amazing and you can feel the emotion in their voices.
Along with dialogue, you get Horo and Lawrence. Both are stunning together. I simply can't get over their chemistry; once more, one of the best parts. But underneath all the fun they have and their smiles is a darker side, one of loneliness. Horo is just about immortal, and through immortality comes those who are mortal, who die while you still live. It's a curse that she knows all too well. And Lawrence is a travelling merchant, one who is always on the move without a real home to call his own but for his wagon. How they're cured of their loneliness by being together is heartwarming and enjoyable to watch.
I could go on about them as they're both great characters and have wonderful traits and wit, but I'll end it with Horo being the perfect gal, adorable ears and all. And that tail, rawr! Other characters are there for plot and our amusement, with brilliant schemes, aiding and forming them and to bring drama and excitement into the pair's lives.
Just give the first episode a shot. It's slow, relaxing, laid-back with medieval economics, coinage and business. It's not the most exciting stuff but it's compelling if you're into economics and an adorable wolf/girl doesn't hurt either. All in all, one of my favorites.