Which to read first?

[Farael]

Originally Posted by Formendacil

The Silmarillion. Unfinished Tales expands upon both the Silmarillion and the Lord of the Rings, and so it is essential to read the former before starting Unfinished Tales.

Seems fairly obvious to me... but that's just me.

I'll second that Formen.... I just finished UT today (Unless you consider the book is not finished if I have not gone through ALL The notes) ... and I wouldn't have understood some of it if I hadn't read The Sil first. In many instances Christopher Tolkien (who put Unfinished Tales together and wrote comments about most of it) will say "This story refers to X episode in The Silmarillion" or "This is X story of Lord Of The Rings as told by Gandalf" and so on.

So most definitely, I recommend you read The Silmarillion first.