Alle responds to: "A query letter's opening sentence: Your recommendations?"
My probably-unpopular opinion.
What are your recommendations, if you are targeting the agent because you found them through QueryTracker? All the workshop I've taken say that the importance of opening a letter with a statement about why you are querying that agent and/or how you found them.
Certainly, if in their query requirements, they ask for an explanation of why you are contacting them, let them know. That does not mean, however, they need the information in the first clause of the first sentence. I feel that the first paragraph is fine.
It is my—probably unpopular—opinion that telling an agent where you found them won't get you closer to a request to see the full manuscript; unless you honestly read a book by one of their clients and you can give one or two sentences (probably one) about:
what about that book brings to mind the project you are submitting; and
how much that book meant to you as it relates to the project you are submitting.
Stay focused on the project that you re submitting.
Sometimes, an agent will appreciate knowing that their advertising dollars in a given venue are effectively spent. However, the primary reasons they will consider your project are (perhaps not in order; perhaps so):
They see a market for the idea;
You have the platform to support that idea;
They love your writing; and
Your project suits exactly what they are looking for at that moment.
As I understand it, most agents plow into the slush pile when they have a need in their list, as opposed to when they read a great query. Making #4 a hard one to nail. Take heart! This fourth item is the reason so many rejections are not your fault or are in any way proof that your writing and/or your idea sucks.
Trust your work and keep on keepin’ on.