I wanted to list my query here, and see what you think. I have a few versions of the letter depending on the requirements of the agent. Here is one such letter:
Thank you for taking time to consider me for representation. I've read your guest-blog post today, and after reading your information and client list at Publisher's Marketplace, I wanted to contact you regarding my first novel THE UNIQUE DESTRUCTION OF AN ORDINARY SOUL (contemporary fantasy; approximately 130,000 words). If I may, a brief synopsis:
Evander is an average young man looking for love and adventure in Baltimore. One lightning-wrought night he finds adventure and so much more when he meets the woman of his dreams, and quickly becomes an honest-to-god, blood-sucking vampire, as our protagonist puts it. And when a master vampire goes too far in persuading the new vampire to live under his House, Evander quickly begins to lose loved ones in a battle that eventually consumes the entire city, while the world heads on a course for nuclear destruction.
I'm currently an undergraduate student working towards a degree in English. Again, thank you for your time [mr. agent]. I hope to hear from you soon.
It's certainly not perfect, but I figured this is short and sweet, and hopefully will get them to read the synopsis or partial.