I live in Vermont, and it's a great place to visit in the summer! Lots of great outdoor activities. I would recommend the Stowe area for a couple of days. From there you can easily hike, there are several options for canoe/kayak opportunities, Stowe has a great bike path, Ben & Jerry's is close by, and it's not too far to Shelburne (Shelburne Museum, Vermont Teddy Bear Factory) and Burlington, where there is a great pedestrian street (Church Street) filled with shops and restaurants.
From here to Niagara Falls is a pretty boring, uneventful 8 hour drive, but Niagara Falls is a lot of fun when you get there (I also agree about the Canadian side.)
Someone mentioned Acadia National Park up in Maine. It's the other direction, but I second that recommendation! It's beautiful up there, and the drive through New Hampshire and Maine is really pretty.
From here to Niagara Falls is a pretty boring, uneventful 8 hour drive, but Niagara Falls is a lot of fun when you get there (I also agree about the Canadian side.)
Someone mentioned Acadia National Park up in Maine. It's the other direction, but I second that recommendation! It's beautiful up there, and the drive through New Hampshire and Maine is really pretty.