These terms all have their own crazy connotations to them. I don't personally know any TG/TS girls who actually like the term "shemale" (although obviously there are some in the porn industry who accept it). I think the term "tranny" is similar, although it's something that I use with some of my friends. We call each other "tranny" in the same way that black guys will call each other "nigger," but I pepper sprayed the last guy who referred to me simply as "tranny" -- and he's lucky my concealed handgun license isn't valid in places that serve alcohol.
Seeing "gurl" in print kinda bothers me. In my experience, it's mostly crossdressers who call each other "gurl" and like to go on about how much they love pantyhose and frilly things and put *giggle* in everything they say, and while I know a few nice crossdressers I certainly don't want to be mistaken for one.
I try not to be a jerk about it. I don't expect everybody to know the nuances of the TS community. But many TS girls are pretty on edge and will jump down your throat for just about anything. Please understand, though, that most TS girls have had abuse and hostility their whole lives and can't help assuming that you'll be no different.
In the US it's actually somewhat taboo among the TS community for a girl to transition but not want SRS (sexual reassignment surgery -- removal of the penis and formation of the neo-vagina). A lot of TS girls have a deep hatred towards their penis and want to get rid of it ASAP, and they don't want others to refer to themselves as TS if they want to keep their penis. SRS is a big deal. These girls have to dilate their vaginas before they can have sex, use a lot of lubricant, and will never experience an orgasm again like they did before surgery. That's certainly not something I'm convinced I want, so I usually just refer to myself as transgendered -- at least around post-op girls. Transsexual generally means someone who wants to fully transition to the other sex. Transgendered is a more encompassing term which sometimes even includes crossdressers.
I'm kinda considered a freak among freaks. If I admit I take hormones and had laser hair removal but I actually like my penis ... well ... that doesn't go over well with most TS girls. They generally want to revoke my tranny card. So I don't go into it too much and just let them assume I'm pre-op and want to get rid of my boy parts at some point in the future. I still mostly avoid referring to myself as TS and just use TG instead. There are some "trannier-than-thou" girls who are overjoyed that they can't get an erection and will totally dismiss girls who feel differently.
Most girls you see in shemale porn aren't even on hormones. They just have boob jobs and long hair and maybe laser. This isn't actually all that common (in the US at least). Most places don't want to give you a boob job unless you've been on hormones for a year and been diagnosed with gender identity disorder by a therapist. This is certainly not the case in Brazil, though. I have trouble defining these people, though. I don't see why you would not want to take hormones. I know a lot of girls have some trouble with functionality when on certain meds, but an endocrinologist could adjust that for you. I'm plenty functional, and I take estrogen, a lot of progesterone, DHT blockers, and a low dose of testosterone blockers.
I guess I kinda got to rambling here...
But what do I want other people to call me? TS or TG is fine. Transwoman is probably the most appropriate. Honestly, it doesn't really come up that often. Anyone who's being polite will generally talk to me like any other girl. But it's not like I'm doing webcam shows. My genitalia isn't really the focus of attention in everyday social situations.
But even the girls who do porn would probably rather be addressed like you were talking to a "real" woman. Sure, she's got a penis, but differentiating between her and "real" women can be interpreted as intentionally hurtful unless you're very careful.