When I first saw the title of this thread, I totally thought you meant transgender, and I was going to call you on your incorrect terminology. However, upon reading, I see that you are actually asking a very interesting philosophical question. Kudos.
Anyway, I love being Bi, and I'm quite happy with it. Back in High School, I just wish I'd known it was an option. I wasn't even aware that such a thing was possible until I went to college. Very liberating. ^^
I wouldn't mind changing a few OTHER people's sexuality to Bi... but that's probably a topic for another thread. ^^
Edit:
Also, being Bisexual, I'd like a firm answer about something. What is the difference between Bisexual, Pansexual, and Omnisexual. Cause they all sound like the same thing to me. Can anyone provide me with a definition that explains this? Or are they all just alternative words for Bisexual?