Lanark: Undoubtedly top 10
Writing about web page http://www.lanark1982.co.uk/lanark.html
Lanark by Alasdair Gray
(Am in the middle of rather a long and 'difficult' book at the mo, so a catch up is offered)
Essentially, Lanark is one of the best contemporary novels in English that I have read. Although Burgess recommended it in his somewhat idiosyncratic list (see link) this should not be held against it.
It is Gray's finest work (although his other books are great too) and well worth the effort.
Am also quite entertained by the website set up by someone to promote the book.
Anyway, regardless of other canoncial exhortations, just read it.