If you buy only one war game ever - this should be the one. A classic and one of the best ever to this day. Easy to learn and easy to play - there are easily hundreds of hours of gameplay here. The whole Panzer General series is great - not a bad game in the bunch, but this is widely considered to be the "peak" game of the series.
If you ever played any of the boardgames, you'll be right at home, if not, no problem. The thing that makes PG II so great is that it simplifies the mechanics, is fairly accurate historically, yet keeps the "authentic" feel throughout. You won't go crazy trying to manage everything and yet you *will* see that rational strategies do work and that things play out in a reasonably realistic way such that you do truly feel like your efforts make a difference on the field of battle. Grand strategy and tactics galore! Armored warfare excellence. Infantry, Sea, Air power, they're all here (but the emphasis is squarely on land forces).
There's a lot of atmosphere, the graphics, sounds, music, etc. are serviceable, but it's the gameplay itself that is the star. The PG series is fun to play. If by chance you've somehow never done so, I highly recommend playing PG II. It's a treat.
I have purchased this series many times over in various forms and it looks like I will be doing so again as the GOG versions shall rule forever more. ;)
Thanks GOG for making this venerable series available!