The NumWorks calculator looks very interesting. Too bad it does not have a RPN mode.
Otherwise the SwissMicros calculators can be recommended. They are all RPN and are modeled after iconic HP calcs. They are just very pricey, especially for non-graphing calcs.
Otherwise the SwissMicros calculators can be recommended. They are all RPN and are modeled after iconic HP calcs. They are just very pricey, especially for non-graphing calcs.