craftgrrl | What stays best on a t-shirt after repeated washings?

I have a question requiring adding things to a shirt. I read the memories and everyone had good suggestions for putting words on a t-shirt...such as puff paint, this regular paint...etc.
But no one said how well they stay on shirts.
Like...which stays best after repeated washes? The paint or the puff paint?
Any help or suggestions would be appreciated.
I am looking for something inexpensive. I could get the iron on letters, but don't they cost a pretty penny?
I have a computer, but my printer doesn't work right and I wouldn't want to print out the image on the proper paper then iron it on. Did that make sense?
I would prefer to be able to do something free hand on a shirt. Perhaps draw on it first and then paint over it.
I am not a stranger to puff paint, I love that stuff, and it was mentioned as something to use. I just have not used the stuff in awhile and I forget how well it stays on after washing.

Thanks!!