I had used a TI-83 calculator for collage, and then when I took calculus I was required to purchase a new calculator.  The one I chose was the TI-86 because I liked the TIs so much.  .  A choice that I have not regretted  since purchasing it in 1999.  It is very well built, the features are clear  and easy to learn and even after being dropped more than its fare share,  this calculator for the last year has worked flawlessly.  I would recommend  this calculator to anyone that needs a calculator that can handle calculus.