When actually speaking to someone, "burst out laughing" is the phrase most often used. If you're going to use "rolling around" or "laughing out loud", usually you would also say "literally".
Here are some sentences I would actually use:
"It was so funny we were literally rolling around laughing."
"The teacher just started laughing out loud for no reason."
"She told a joke and I literally burst out laughing."
I find that when speaking, it sounds a lot more natural if you use something like just/randomly/literally, because it's rare to actually be bursting out laughing or rolling around so it emphasizes the intensity of the situation.