My all-time favourite book.
I read it at around 8, the first remotely adult-orientated novel I opened. The Watership Down setting/story conjures images/feelings (i feel books in my head, rather than seeing them) that are of a completely different essence than anything I've read later. I am still searching for a book that offers the same dreamlike, while at the same time epic, feeling, but unsuccessfully (LotR and perhaps parts of The Golden Compass came a little close, but that's that). I think I'm just too old to ever have a reading experience remotely like Watership Down again.
Only recently (with a nudge from Michael Moorcock's "Epic Pooh") I've actually thought the book over critically, to see if it's actually any good. Compared to my more recent reads, it's rather mediocre. The descriptions and the universe (what kind of creature is King Darzin? No explanation - excellent!) are great, but the characterization is dowright poor - one character rarely has more than one characteristic (if any. Who were Speedwell, Buckthorn and Acorn?). The sexism of the book is also pretty extreme - I can still see no reason for all but one (and she's more of a damsel in distress type when she enters) of the characters to be male, nor for the cold, instrumental way the males related to the females (I mean, these guys die to save each others, and the females are never more than reproduction machines).
And the follow-up, Tales from Watership Down was dire. It was hard to believe they were written by the same person. I tried The Plague Dogs as well, but couldn't get into it.
But there's no helping it; Watership Down is, and will probably remain, my favourite book.