Being a large man (6'3" and 360 pounds [down from 406 pounds]) I prefer bib shorts as the regular cycling shorts tend to get the waist band pushed down and are uncomfortable to me.
That said when I was concerned about how people perceived me I would wear regular cargo shorts over the bib shorts.
Anymore I just wear the bib shorts or bib tights with a cycling jersey and ride on. I figure those who would point and laugh are those who wouldn't try to better themselves, and those who don't point and laugh are very supportive of me trying to better myself.
I do wear fun jerseys with prints on them that are humorous, and get many comments on the jerseys.
For bibs I started with Aerotech Designs, but as I shrank I moved to Belwether and now my preference is Endura brand bibs.