Tour companies for Giverny/Monet's house and garden?

It's pretty easy to do this without a tour company if the trains are not on strike. We stayed on Ile Saint-Louis, took the metro to the train station (Saint-Lazare), train to Vernon, tourist shuttle train to Giverny. On the way home we walked from Saint-Lazare, which took over an hour but we stopped for ice cream and to photograph the Louvre at sunset.

Check out Paris City Vision. I did their tour to Giverny, which included Auvers-sur-Oise, but they probably have trips that just go to Giverny. My trip was a small group in a mini van and we were picked up and dropped off at our accommodations, and lunch was included. I enjoyed the day, especially my pleasant travel companions - there were just 3 of us. At Giverny, our driver took us to the group entrance, which leads directly into the pond area, then we were left on our own to explore. The tour also included the nearby Impressionist Museum. If you are interest in Van Gogh, I would highly recommend this tour that includes the village where he spent the last few months of his life.

Whatever you do, be sure you book directly with the tour operator, such as Paris City Vision, and not with a third party broker, such as Viator. I have done other tours with Paris City Vision and have found them to be very reliable and they deliver what they promise.