I got the Big Shot pro - because it can use Go dies, Sizzix dies, and some of the Studio dies. My first die was the log cabin die - because I wanted to try one and I did not want to have to cut 1 1/2 inch strips and then sub cut to the desired length. Then I got the 1 1/2 inch, 2 inch, 2 1/2 inch, and 3 1/2 inch strip dies. I also bought the winding ways die(because it is on my bucket list), a triangle in square die (think tri-recs), a double wedding ring (another bucket list item), the Studio English paper piecing hex dies. I have bought a couple of multiple square dies - even though I could cut squares using the strip dies.
My next project is to make a list of my dies so that I don't buy the same thing more than once. LOL!