Yes, that series is really good. The calcs I use most often: * HP-25 (yes, a nearly 50-year old calculator, but you can hold it in one hand and it does most th

Yes, that series is really good. The calcs I use most often: * HP-25 (yes, a nearly 50-year old calculator, but you can hold it in one hand and it does most things I need very well) * HP-11C or 15C (doesn't matter which, I don't use the extra features of the 15C) * HP-12C * HP-50G (very useful for unit conversions)