I'd love to set up a secret "grow room" in my house, but I don't want to break any laws. Are there any legal plants that would thrive in a marijuana drug lab type setup?

Breeding and growing the plants has to yield high profit or it's not worth the expense.
I just think it would be fun to have the whole setup. If I had money to burn, I'd grow ferns, just so I could take people on a tour of my house and say, "Oh, here's my marijuana drug lab. I'm kidding! Those are ferns." It's unrealistic, of course, since I don't have money to burn. If I could grow some legal plant for profit, though, then I could do that and still pretend.