Gaining

As a skinny dude myself, I've attempted gaining multiple times, but responsibilities have previously prevented me from gaining more than 25+ lbs and now I'm really motivated to gain for real. For the pigs who used to be twigs, at what point was it where you were truly excited with your progress and decided to become unmistakably fat?

I agree. It was when I reached around 225 pounds that people started to comment on my weight gain and was occasionally called Fatso. Although I was technically obese, I didn’t feel obese. In fact I did not feel that different from when I was skinny. I was developing a prominent belly which rolled over my waistband. Since then I have put on a lot more weight.

Now! I've always been skinny and after gaining nearly 35 pounds I'm starting to feel the chubbyness

Just approaching 200lbs here, and starting to feel chubby (height 5' 10"...). I think a max of about 250lbs would look great on me, depending on how I carry it, but personally anything over that I think I may find a bit too restricting.
Definitely starting to look chubby, so 'roll on' (excuse the pun) when I look fat.