While not the highest mountain on the planet, Chimborazo has the distinction of being the furthest point from the centre of the earth, because of the earth's geometry. The earth bulges at the equator due to it's rotation, making Chimborazo further from the centre than Everest.
Why choose this bucketlist goal? Well, it's certainly more financially attainable than climbing Everest. Secondly, it's a volcano, which means that it has a significant prominence over the land, and therefore the views from the top might be pretty epic. Thirdly, it's in Ecuador, and there's no shortage of awesomeness to conquer in South America.