One Workman to Another

A number of writer's-market-type-guides advise authors to be aware of the market, of who's publishing what. Fine and dandy. But many of them further recommend that you demonstrate this knowledge in your query letter by comparing your manuscript to "similar" offerings from said publisher -- in other words, explain why you think your story is a good fit for this editor and/or house with concrete examples.
Am I the only one who thinks this is bound to come off as pretentious at least 80% of the time? I'm a part-time bookseller, and few things make me want to pluck out my eyeballs as much as catalog copy that assures me a new fantasy is the "next Harry Potter" or that a historical novel is "sure to appeal to fans of Dear America." I end up muttering, "Oh puh-leeze!" and turning the page. (I also sniggered mercilessly when Jenna Bush compared her book to Number the Stars and Anne Frank's Diary of a Young Girl .) Just let me read the dang book and *I'll* decide what it reminds me of, thank you very much. Besides, I don't know about you, but when I give a new book a shot, I'm mostly hoping it will be somehow DIFFERENT from the other gazillion books I've already read.
In light of that, how can an author appear well-informed and familiar with a publisher's taste without going too far and coming off as a conceited nitwit?

While it's nice to see that people have actually done a little research, you're exactly right. Most of the time that skimming of our website does not result in a particularly better-targeted submission or a significant understanding of how my publishing house is different from others. And yes, absolutely, I don't care what you think your manuscript is like unless you give me a good reason to think I might agree.

So here's what would really make a difference: mention a couple of our titles that are in some way similar to yours (e.g., in the same genre and age range, or on the same topic but in a different genre or age range) and tell me specifically what's strong about them. Don't use filler words like "sweet" or "charming" or "great" which essentially mean nothing. Think like you were in a Masters program on children's literature and say precisely what one of our books' strengths are. Showing me that you are aware of the ingredients of a good manuscript rather than simply your reaction to it sets you apart.
You know, most people enjoy any cake that is pretty and palatable, and that's about all they can say about it. Other bakers, though, can tell that this one has a good crumb and a touch of nutmeg and that the type of icing is a good match for the texture and sugar content of the cake. Talk to me like that. Show me you know the difference between pretty and palatable, and pretty and palatable and well-made.