Ideally all 3! as they all have their strengths, I'm after the 1st one although I have seen it and have the 2nd and 3rd editions, unless you really want the up to date models included, for me the best one is the 2nd edition, which covers up as far as Dedra, and was first printed in 1991.
although it's mostly black and white the quality of the paper and the photos are superb, whereas the 3rd edition has a lot more colour, it can't match the 2nd edition for quality.
If you want a 3rd edition a copy can be had new from Holland for about £110 including postage,
This is compared to the £65 when first printed in 2006.
If you just want a good general knowledge book on Lancia's up to Beta including a lot of road tests, then for a lot more reasonable cost, have a look at the Hamlyns "Lancia" Book with all information from 1908 compiled from the archives of Autocar.
"It includesDescriptions and Technical articles, full road tests and driving impressions and coverage of Lancia's wide-ranging activities in racing and rallying" This was my second Lancia book and I found it a great help in understanding the Marque and the Ethos.
Brian
8227
ISBN 0 600 34934 9 first published in 1981.