Too many variables to say anyone is best over another. Shop around and compare what's available to you. In general fully aluminum pools will resist corrosion and last the longest. Composite comes in second and steel last. A lot of "composite" pools have only composite top rails and lots of steel parts mixed in reducing their corrosion resistance. From what I learned in my hunt for a pool is a cheap pool often is just that. You will get what you pay for when you shop around and do your best to compare apples to apples. One final thought from reading this site is that no matter what pool you get if it's installed well and taken care of it will last you many years. Installation of the pool and it's maintenance are just as if not more important than the pool itself for how long it will last and how enjoyed it will be.