There's really only one label that I've ever had someone try to push on my that I absolutely hated. That term is transmasculine. I dislike that term; it makes it seem as if we're dealing with the sociological definition of gender. Being trans is a lot more than wearing "boy" clothes and getting a "boy" haircut. Ugh, I hate it when people try to associate being trans with gender roles.
I don't have a problem with FtM. Why? Because my biological sex was female. As much as I wish I wasn't, I can't delude myself into thinking that I wasn't born with female parts. Now, however, I'm on hormones. My body is adjusting itself, becoming male. And eventually, I'll have top and bottom surgery, to fix my body even more. And by doing that, I did go from female to male, physically. That's actually why I like the term transsexual over transgender. This has never been about gender - my gender identity has always been the same, and my gender expression is irrelevant. It's completely about my body's sex.
Of course, my brain's sex has always been male. I've never been female in that aspect. But, my body had to catch up to my brain and that's why the term FtM fits.