My System was my second chess book. I bought it in an underground book market in a forest for 10 roubles when I was a 9 year old.

It is a great book and without it I would have struggled to reach FM, but it is a little bit too advanced for a first book. I'd say it is a good 4th or 5th book.

I'd say something like Lasker's manual of chess would be better suited as a first book. Perhaps one of the other starter's volumes from Seirawan, et al would fit the bill.

seconded. No single book made a greater difference in my playing level. Reading this at a relatively young age made me a far better positional player than everyone else around me.

This is a great intermediate level book. Definitely read Reinfeld and study the SCO and then get into this one.

Tactics!