I thought the metamorphmagus thing was just the coolest thing ever. Her being an Auror and having the ability to change her appearance at will was so fascinating to me. At the same time,she's super clumsy and really funny. I thought that was such a nice contrast. What with being an elite,highest rank 'officer' and yet randomly trips and breaks half of your house, priceless. Plus,she's a Hufflepuff aka the coolest house!
The thing I like the most is the sense of humour part. I remember dying of laughter at her convo with Ginny:
Tonks: I was never a prefect. My Head Of House said I lacked certain necessary qualities.
Ginny: Like what?
Tonks: Like the ability to behave myself.
Such a simple,yet hilarious line. Also,her sending the letter to the Dursleys,saying that they are in the 'All-England Best Kept Suburban Lawn Competition' had me in tears. I love that random humour!
And I loved that JK hooked her up with Lupin. Older,serious and composed vs. young,loopy and enthusiastic. Again,nice contrast.
And,after all the sh*t that went down,in all the books,her death was the thing that shook me the most. Not Dumbledore,not Sirius,not Dobby,not even Fred or Lupin. Tonks dying left me numb. Literary. Even now,just thinking about it. I can't believe JK killed her. Yeah,it's a nice parallel,with Teddy and Harry,but still...it's plain cruel! And after learning that Tonks was originally supposed to live,but JK killed her to compensate for Arthur surviving in the Order Of The Phoenix,I was beyond pissed! Tonks was the perfect character.
-now I'm upset again-