I've been querying agents and have gotten a partial or full request from quite a few, but I seem to get stuck at the last step: an offer of representation. They give the same reasons - they like my writing, my plot, even my characters, but they just don't fall in love with the novel.
As an example, the last agent (who had a partial) said: "You have a great imagination - I love the premise - and you're a good writer, but I'm sad to say that I just wasn't passionate enough about this to ask to see more. I wish I could offer constructive suggestions, but I thought the dialogue was fine, the characters well-crafted, and the plot well-conceived. I think it's the kind of thing that really is subjective - why some people adore the book on the top of the NYTimes bestseller list, and others don't." I've received similar comments from other agents.
What should I do? I don't even know what I'm doing wrong.
You're not doing anything wrong, you're just not doing something that excites agents and gets them to keep reading.
My esteemed colleague Jenny Bent (who knows a thing or ten about good books) once tweeted that pacing was the single biggest problem she found in requested fulls that she didn't offer to represent.
Clearly you need help with something. This is where you find a brutal critique group or enroll in a year long class (Grub Street offers this kind of workshop.)
You don't mention which novel this is for you: first, second or Nth. I remember Jenny Milchman saying she wrote something like nine novels before her "first" published novel.
It takes a long time to learn to write a good novel. Clearly you've got talent if you're getting requests, but maybe you're just not quite there yet. (Remember the 10,000 hour theory made famous by Malcolm Gladwell)