I'm not sure what you are looking for as far as unique, but the Adirondacks are one of my favorite places in the world and a place I have spent a ton of time in. One could easily write a book about the areas you are asking about. There is some outstanding fishing, but it depends on when you will be there. To me, the quintessential Adirondack experience is a backcountry trip into the ponds for brook trout which are often measured in pounds rather than inches. These trips are usually best as an overnight with a canoe which you can rent at a number of places. You will have to do some research though as acid rain has impacted some to the point that they are fishless.
There is also some very good trout fishing in streams near Saranac lake. The Ausable is the most well known stream and has miles of good pocketwater. Other good trout rivers are the Saranac, the Salmon near Malone, and the Chateugay. These are all pocketwater rivers with a mix of wild and stocked fish depending where you are. Some of these can fish pretty well throughout the summer, although this summer has ben particularly dry out there. There is also good warmwater fishing in sections of the Saranac and in rivers like the St. Regis. It really all depends what you are interested in. But there is more fishing within an hour of Saranac lake than you could cover in a lifetime.
There are a couple of very good fly shops up there, I would recommend giving them a call. Wiley's Flies is my favorite.
Lake George sucks. Worst part of the Adirondacks.