Shogun by James Clavell.
Genius. I’ve read this a couple of times now and really love it. It was the first “big” book that I’d ever read and I found it totally compelling and un-putdownable. 
I haven’t read it myself, but I remember fellow L&L’er David getting this from the school library when we were around 14 and raving about it - I believe it was the first “big” book he read, too. I’ll have to read it one day…
I highly recommend it KB. The way that Blackthorne becomes more and more immersed into the Japanese culture as the book progresses is fantastic, and in Toranaga, you have one of my favourite characters in literature anywhere! (along with Jack Reacher!!)
I agree that Shogun is a great book. In fact, I’ve looked for similar reads and have found most wanting. (Epic tales where a westerner becomes emersed in a foreign culture.) I also found Clavell’s novel King Rat to be very engaging.
His other books,
King Rat
Tai-Pan
Sho-gun
Noble House
Whirlwind
Gai-Jin
All loosely connected and are epics worth reading
Wickepedia them to get an overview on the books
Grandad8
One of my favourite all time books. I first read it as a teenage and found thoroughly engrossing and moving.
This book is one of the most interesting book I’ve seen. And as you think It totally compelling and un-putdownable