So many things. I was initially ambivalent about hormones, but I didn't want to look like a 15 year old for the rest of my life. After going on them I felt right, like I had been holding my breath all my life and could finally breathe freely.
I love the way I smell now.
I love my voice. I still play with it and enjoy noticing the new parameters. I recorded it recently, and hearing the playback was weird but my voice isn't as nonstandard as I thought it might sound when I'm not listening from inside my own skull.
I love being physically stronger and more emotionally resilient. I rarely get injured anymore, and if I get hit or yelled at or made fun of I don't immediately cry like I used to.*
I wish I had more face hair, but I love the hair I have grown with T. Most cismen I've been with didn't have the amount of hair I have below the waist. I'm even starting to get hobbit toes.

I love getting fat. I'm not obese, just overweight, but I spent most of my life too skinny and without much hunger. Now I don't feel like I could blow away in the wind, and I feel like my little potbelly helps cue to people that I actually am in my thirties.
I love that my skin no longer rashes up at the slightest exposure to the wrong soap or whatever.
And it's cheap and unfair, but I love that simply being on hormones is enough to convince medical staff and bureaucrats that I am a "real" man, or at least really transgender. Many of my transition barriers melted away after I started receiving testosterone treatment.
*this sounds bad when I reread it, so I feel like I have to add that I am not in an abusive relationship. I take care of a developmentally disabled person who has some issues with violence, and the times I get made fun of are usually by teenagers on the street who see both of us as uncool peers.