My thighs, for sure. Even relaxed fit jeans are almost always too tight in the thighs and too big in the waist. I’m fat enough now that I have a decent sized belly, but my thighs are enormous.
On my wife it keeps changing in stages as she gains.
First it was her breasts and belly. Then her gut started getting bigger. Then her thighs, which have now started hanging down in the back. She's gained a second rear end of "thigh cheeks" even bigger than her ass. But recently SHE brought it to my attention that her arms are getting huge and flabby, and she loves the way they jiggle.
has to be my belly, and loosing a touch of weight has made it sag and hang much lower, it has certainly taken over and now hangs and wobbles to its own devises
As a male, the stomach gets most of my fat, however I have a large backside and hips aka saddle bags as well, recently gains have also increased on my moobs, arms and thighs with rolls forming over my knees and on my back as well, all enjoyable as you find fat pushing and folding in new places as you move, sit or lying down.