Details: (c) George Allen Unwin Ltd 1980; Pub Unicorn (Unwin Paperbacks) 1985; Edited by Christopher Tolkien; ISBN 0-04-823208-4
Verdict: The Unfinished Tales are OK, but not particularly inspiring.
Reasons for reading it: I am interested in the background of LotR.
How it came into my hands: lethargic_man lent it to me.
Unfinished Tales has most of the same flaws as The Silmarillion, only more exaggerated since it is even less finished. And reading it felt a lot too much like work, with all these textual variations and cross-references and stuff.
There are a few nice bits; I like the Númenor section, since I'm interested in that setting and it's very little developed even in The Silmarillion. The story The Mariner's Wife in particular is a lot more complete than some of the stuff in UT, and I appreciated the portrait of a marriage which fails not because the pair do not love eachother enough, but because they have incompatible life goals. (And yes, I am projecting a little.) But basically I don't read Tolkien for dissection of romantic relationships.
I also liked the little snippet of interaction between Gandalf and Thorin (The Quest of Erebor), but in truth this is probably largely because it involves characters who are already well established in LotR. This story also reminded me that I haven't read The Hobbit since I was a kid; I have to admit that while I remember enjoying it, it never grabbed me particularly, and doesn't really stand out from a whole lot of other books I enjoyed at that age.