It depends on the costume. I can't really think of any other would be perfect for, but I think some costumes are implied to be made out of it - twill, at least. I feel like broadcloth can work for some things, but is almost never the best choice. It can be made to work passably and even well, but not the perfect first choice.
Usually there's a better fabric but I understand that budgets come into play! Cotton twill usually plays into my "budget" fabric suggestions when people are looking to save money.
Actually in the pipes:
- Remaking Ser Loras doublet.
- Luke Skywalker, A New Hope
- Wind Waker starter costume in swim material
Eventually: Paul from Dune, Faramir, Harry Sullivan