Cruising the canals of Europe is pretty much a European experience. There are canals elsewhere in the world but the culture of luxury barges sailing slowing through the countryside has only developed in Europe.
We do need to draw the distinction between Barge Cruising and river cruising in Europe. The river boats commonly accommodate 100 to 160 guests. Most barges might hold 6 or 8. The large ones could take 20 guests. Sailing on canals is a very slow process. You might decide to step off the barge and walk or bike along the canal paths - the barge will not disappear out of sight.
The beauty of river cruising in Europe is that you get to visit the small towns along the river. With barges, the towns just get smaller.
Practically all barges tend toward the luxurious - excellent accommodations, food and wine but also prices that reflect that luxury.
Companies that specialize in barges include: