Lake Placid, NY is possibly one of my favorite little mountain towns. I've trained there for several summers when I was younger (for figure skating) and every season there is fantastic.
If you can also manage to be there during the Ironman-Lake Placid, it's a definite must-see! It was so inspiring to watch the swimmers take off together and the camaraderie during both the bike and run portions is amazing.
I'd also recommend visiting in the winter (when the Olympic Games were held) to get a real-feel of how the town was during the Olympics (it really hasn't grown-up too much). There is so much to see and do there, that you really don't need a car once you get there. The only thing that is really out of town is the ski mountain or ski jumps, but I think there are buses that will take you to both!