I've given the same advice to two author friends recently and it occurred to me, why not post it at Promantica (aka, the most anorexic blog on the planet)?
Of course you don't need to read the post; my advice is in the title: Write the book you'd love to read.
I've enjoyed books by some of these authors, and not the books by others. Some books aren't particularly well-written, which clearly doesn't rule them out of "Ohmigod, you have to read this" status. (In fact, I've come to the conclusion that "the writing's not very good" is often a justification of someone's dislike of a book, but "it's very well-written" is never a selling point in the "No, really, you have to read it" urging.)
Here's the thing. I may never sell the voluminous quantities of these authors because to do so, I'd have to write books I don't personally want to read. How much fun would that be?
Oh, I don't think anyone's writing to the market--those bestselling authors are writing the books they'd love to read, and they've tapped into a huge readership that happens to love the same things.
Sure, that could happen to me, but I'm okay if it doesn't. Sales numbers, book rankings, and author status are all very nice, but they're ancillary to what I can control: the words on the page.
A lot of that is about good writing--believe me, that's the easiest thing to learn or fix--but a lot of it is about the storytelling, which is much harder to gauge.
So what sorts of things are true about books I love to read? Less tension between the hero and heroine. I know this means my books seem to have less conflict, but as I don't like to fight, I don't like to see my friends and family fight, I don't even like to overhear strangers fight, why would I want to write about characters who spat all the time?
I like angsty emotions, black moments, and heart-wrenching endings. I love five-tissue weepy reads!
I like sex but if I'm being honest, I can take it or leave it when it comes to a romance I love. What is required is that any sex be specific to those people and that situation.
And I like smarts. Characters with smarts. Plots with smarts. Sassy dialogue. Clever situations. I don't need the characters to have advanced degrees, but if they do, I expect them to act like they do. On the other hand, a street urchin can be credibly inventive. I love that too.
I like characters to be comfortable financially. Rich is nice but not necessary. Just not broke. That said, Rachel in Susan Elizabeth Phillips' Dream a Little Dream has to be poor for the plot to work.
I'm sure there's more, but you get the idea. Right now, I'd say I'm writing books I'd enjoy if they were by another author. Not sure I'd love them to the point of saying, "No, really you absolutely positively have to read this!" Maybe someday.