Yes, I'd second everything HareBrain says, telford. I can see where TEiN is coming from, but I don't think an attention-grabbing first line is actually going to do you any good. In fact, quite the reverse.
Writing is a business, so you should be writing a business letter. A soft business letter, perhaps, and with a hint of excitement -- the epistolary equivalent of a well-tailored suit in a cashmere mix but with red killer heels. Or a red hankie in the breast pocket for you men. (Though you can wear the heels if you really want...)
TJ (and others)
I wasn't suggesting that it should be attention grabbing just for the sake of grabbing attention.
I was suggesting that the first thing they see in that letter is the most important thing you wish to say about your book.
I suspect, (oh yes, I could be absolutely wrong with this one) but how many times in a lifetime do you need to read
Dear Mrs. Agent...
before you start to get fed up with it and skip it.
It took me about 20 times. (in fact if that topic line hits me between the eyes I don't care who it's addressed to. I'll read the rest.)
Uncommon Purpose: A tale of galactic daring do - or whatever.
Dear Mrs Agent,
Please and so it continues in a suitably grovelling manner. It makes her feel good about herself maybe but as a start to the day it's all very tiresome and repetitive stuff.
OK, now I know what I'm in for. Am I interested - well that depends on what that line said, but I'm under no illusions. This writer is telling me he means business. The niceties are there, he knows my name but he appreciates I'm a busy person and if that line doesn't ring my bell he understands I'll go no further. I can skip the pathetic pleading 'please please be my agent' bit and get to that important meaty synopsis bit. In fact I'd be tempted to miss out the please be my agent bit altogether.
Why else would this bloke be writing to me. So straight in there with the
And, if I like it I'll find out how to get in touch with him, no doubt somewhere his address or email will be lurking in this.
Dear Mrs. Agent,
"Uncommon Purpose" is a tale of young love and space pirates ...
...
Into this highly delicate political situation is thrown Grob Wilksamer, a young grudge bearing cadet in his final year at the Galactic Space Academy. He really joined the service to avenge the death of his mother and sister at the hands of these evil space pirates and has sworn, on his life, to the pluck out the eyes of Scrott Argwhamer, the captain responsible.
and so on
As I said, Just a different take.
However, there must be something that makes agents read other peoples submissions before others. Could it be that they get enthused by the tone of the introduction of some over others.
Now if you look up what's the thing that catches your attention. It's that opening line. It might be a crap line (as above) but there is no doubt what this letter is about. That's why nearly every every business introductory letter starts with one.
Maybe what we need is a challenge to write an introduction letter and vote on what people (if they were agents) would be interested in.