I've been choosing books to read based on whether or not they acknowledge their agent.
No point in wasting time on pleasure, when there's work to be done. If a personalized query is needed, you can't do better than to reference an agent's client, to show that you've done your research and are reading what's currently out there. You're market savvy, dropping those names like breadcrumbs.
If you're writing women's fiction with a touch of humor, you'd want to query Molly Lyons who's currently at Joelle Delbourgo's agency. Your manuscript, which deals with the relationship of a thirty-something who's coming off a bad break-up, would resonate with fans of Lynn Kiele Bonasia, author of "Some Assembly Required".
After reading the book, or skimming it at any rate to get a taste of it, I realized that I have to rewrite my manuscript to lead with the female character. I've already done the bit about giving over one chapter to her and then follow with one chapter from him, back and forth as their relationship progresses.
There's wit, just a touch, there's danger, the female protagonist saves the day, and my manuscript would be a perfect fit for Molly Lyons.
Assuming that I manage to catch her at the right time, when there's a gap in her client roster and she's looking to repeat a past success.