At the National Gallery and paying some attention to 17th Century Spanish paintings, I came across a Velázquez, Philip IV hunting Wild Boar (La Tela Real) :
It is quite a large picture (182 x 302 cm) and a very good piece of work, but not one that grabs you like one of his portraits or religious paintings. There's a lot going on and what is particularly well done is his attention to the figures. He captures each one with a few strokes of the brush, no extra fine detailed work but enough to capture the whole. All the (many) figures look good. This ability to do so much with so little effort is why Velázquez is a great artist.