Once you acclimatize to the altitude (11,000 feet), Cusco is a pleasant, but very touristy, small city. With the wealth of archeological sites in the area, it's one of the most popular destinations in the Americas. There's some pretty colonial architecture (including a fabulous cathedral), pleasant plazas, an excellent museum of Pre-Colombian art, some other museums of passing interest, and good restaurants in all price categories (more and better than I had expected, actually). But don't expect a vibrant nightlife. One goes to Cusco for the local culture, but not "capital-C Culture."
Overall, though I haven't traveled widely in Latin America, I've enjoyed other cities, like Oaxaca and Havana, more, but one thing Cusco really does have going for it is the warmth and hospitality of its people. And though, as with any tourist center in the developing world, you're bound to be approached by people trying to sell you things or provide services for tips, Peruvians know how to take "no" for an answer, so it's not trying on the nerves like, say, northern India. The one thing I'm really thankful for is that, outside of a few touristy cafes, musicians playing endless variations on "El Condor Pasa" were not ubiquitous.
I plan to post a bunch about what I ate in Peru, a brief encounter or two, and a bunch of photos. For now, though, just to whet your appetite, here's a photo of a mystery dish. Details to come.