The HP 12C calculator just turned 30. It remains the dominant financial pocket calculator, and is still the recommended calculator for most finance courses including CFA and CPA exams. In addition to the financial functions and RPN notation that make complex financial calculations quick to perform, it also features a very long battery life and buttons that almost eliminate false keystrokes.
New limited edition versions of the 12C and 15C are available from HP’s special anniversary page for US$80.
Personally, I think the HP 42S is the ultimate calculator. More recent calculators have inferior keyboards and too much emphasis is placed on graphs and menus. I wish it was still available. Maybe in 2013 HP will release a 25th anniversary edition. I can only hope.