Definitely go for the TI-85. I have both an 85 and an 82 and the TI-85 is much more powerful, can be programmed in assembly, and (in my opinion) better menu systems. Also, with the TI-85, you have the benefit of a catalog (list of all the calculator's functions and commands) so you don't have to memorize a bunch of key combinations. I say go for the 85. I promise you won't regret it.