I haven't been to the Van Gogh exhibition in Basel, but I heard that there were long queues, at least a month ago.

I was at the Van Gogh Museum in Amsterdam and was amazed by the paintings. They even had sculptures from Van Gogh. This was an unique and fascinating experience for me.

Since I haven't been to the exhibition in Basel, I can just give advice for avoiding queues at the museum in Amsterdam. Fridays, they are open until 22:00. I went from 20:00-22:00 and this gave me enough time to look at
the Van Gogh collection and another modern collection on the topmost floor. At 20:00, I was the first in no queue at the ticket counter. The Dutch woman at the counter told me I had chosen the best time, esp. the most quiet time during the day!