This is the first comic TG Comics actually asks you to pay for, but it is definitely worth it.
Brownsville is made by Tebra, one of the leading artists in the TG genre.
Dr. Paul Angstrum is a genetic research scientist at Brandell University. Due to an experiment his son gets a new life as a woman, something that changes the dynamics of the whole family.
You have to sign up for a premium membership of the TGC Forums to pay for and access the comic.
UPDATE: If you're an existing TGComics Forum member, you should convert your existing account to a free, premium account rather than make a new one. (See comment)