First Lines

Instead of boring you with the trivial matters of my everyday life, today, I shall look at a very crucial aspect of literature: First Lines. Being the first thing one reads of a book, they can serve a valuable purpose in both setting the general tone of the book, and to draw the reader in. However, many first lines fulfill neither of these roles, yet go on to be absolutely amazing books. I'm not going to try and establish a link between first lines and the quality/type of book, as that is beyond my scope, but I will look at some examples.
[Note - I shall define first lines as the first sentence of the first chapter, ignoring prologues/introductions/etc]

We shall begin with JRR Tolkein's class, "The Lord of the Rings."

"When Mr Bilbo Baggins of Bag End announced that he would shortly be celebrating his eleventy-first birthday with a party of special magnificence, there was much talk and excitement in Hobbiton."

Here is an excellent example of one of the first line's functions - establishing background. Three names are mentioned, to give the reader a sense of knowledge and familiarity immediately, and also to establish a link with the trilogy's prequel, "The Hobbit."
From this first line, we can imply that Hobbiton is a close-knit and friendly community, without many troubles - an impression built upon in the next couple of chapters, to provide a stark contrast to the deepening darkness of the rest of the book.
Tolkein also establishes key facts of the world in which the book it is set - not our own, yet related to it. An unknown word ("eleventy-first") gives us a sense, however minor, of foreignness and curiosity.
Altogether, a rather unwieldy first line, yet one that fits in well with the theme and purpose of the next couple of chapters.

Next, Bernard Conwell's "Enemy of God":

"Today I have been thinking about the dead."

A stark contrast to Tolkein's line, this one serves an entirely different purpose. It gives us no information of the world in which this is set, but it is short and dramatic, establishing immediate intrigue and drama.
It is very striking, by the use of the first person, the immediate tense, and the use of the word 'dead'. Instantly we are set to thinking about who this character should be, which dead, and most importantly, why. However bad the rest of the book may be (I have no idea, I have never read it), the author is guaranteed for the reader to read on at least a couple more paragraphs before they gauge the quality of the book.

Next, Ian Rankin's "Let it Bleed":

"A winter night, screaming out of Edinburgh."

Again, a very different style. Rather than a character-based sentence, this one is purely abstract, with no mention of any personification. However, it does immediately let us know that it is set in the modern real world, that which we live in (at least, it does if you've heard of Edinburgh). It also creates immediate excitement, encouraging further reading.
This sentence is also quite cryptic - it makes little sense when read individually. We know that there is a winter night, and something screaming out of Edinburgh - but no hint as to what the 'something' may be, whether animal, vegetable or mineral.
Personally, I thought immediately of a car leaving Edinburgh at high speeds, but I don't know about the general impression.

More later. Comments encouraged.