I have a copy published by Random House that IS my Bible. I have never purchased a copy and I do not discuss AS with strangers but on two occasions business associates have given me a copy out of the blue. The first was from a young intern that worked with me during the summer of 1966. The second was my hard cover edition that was given to me by some British engineering executives after a two week visit to our facilities in 1977. I think that they each believed that I had no read the book but through my actions and words knew that I would like it.
The hard cover edition will not take another reading because the pages are yellowing and it feels very fragile. I reread it last summer and it caused some interesting comments. First a very proper looking matron in a waiting room asked what I was reading and when I showed her, she said "you should be ashamed of that". Second, my very bright 10-year old granddaughter asked what was that old book and I told her it was my favorite book and that when I died I was going to leave it to her. She said what she always says "why?" to which I said because I want you to promise me that you will read it. She said "no, I can't promise that because I may not want to." I said "Grace, anyone that would say that will not only read it but will love it."

I like it on my Kindle.

I have a copy with the green-and-black cover; the dust jacket shows the railroad tracks leading off. It has the original copyright date, with "21st Printing". I've had it so long I don't remember when I bought it - 30 years ago, at least. I keep it by my computer to consult now and then, which put paid to the dust cover - the book is fine. I can recommend it heartily.
If you were to store it in a nitrogen-filled atmosphere, it would last longer. Sounds improbable, but one also preserves partially-drunk bottles of wine by forcing out any oxygen with nitrogen. You can buy a can of nitrogen at any good wine store. Warning - it will feel empty and won't make a noise when you shake it. Storing it so, however, would make reading it somewhat difficult - defeating the purpose. ;)