HP 48g - Great engineering calculator
Pros: Quick to use, Lots of memory
Cons: Adjusting to RPN, Too many extra features
The HP48G calculator is a standard for engineers. I bought mine 7 years ago, and it is still front of the line. The Reverse Polish Notation (RPN) takes a few days to get used to but after that it is much quicker to use and far more convenient - especially if you regularly use constants.
The ‘stack’ on the calculator is unbeatable - you can scroll up and down hundreds of stored values and use them at will. There are many other functions on the calculator - stored constants, equations, pictures, animations, games, and tons of other stuff that I find really useless. All I use the calculator for is the general engineering calculations, and it is flawless for that.
I used my HP48G through high school, college, and now grad school. I have used it in all my work placements, and never had problems with it. The batteries last about a year with regular use, but there is a low battery indicator that starts warning you a month or so in advance of battery failure. This makes sure you are prepared during that lengthy test!
The HP48G isn’t for everyone though. I haven’t met an engineer who doesn’t love it, but I haven’t met a biology type that likes it, either. For a solid, speedy calculator for everyday use, I highly recommend the HP48G.