Haha. Anything that fits. I think the biggest problem is when people don't realize they've outgrown their clothes. As long as you find things in the proper size, you're fine. When I was on dating sites, one of the guys I chatted with at length had a shirt like that on in one of his photos. It suited him, and he was a larger guy. I see nothing wrong with it.
I like my clothes to be a bit roomy/ baggy. So I always know when I'm putting weight on before I outgrow my stuff. I can't stand close-fitting clothes, I don't know how people do it. Especially guys who wear really tight pants. UGH!