I would kill to tickle Emma Watson but she has said she isn't ticklish (doubtful, but claimed multiple times), so I would tickle Emma Roberts. Plus Emma Roberts is pretty hot herself.
When it comes to tickling a famous girl named Emma, I would prefer Emma Stone TBH. She is such a wonderful creature.
But between these two I would go with Roberts. Watson already confirmed that she is not ticklish, so I don't see the point. Emma Roberts is pretty hot too and she has very nice feet I might add. Not as nice as Watson's, but pretty damn cute.
I'd love the opportunity to try to prove Emma Watson wrong. She could be lying afterall. But if she really isn't, I'd gladly take Emma Roberts as a consolation prize. She's beautiful and she has lovely feet.
Even people who generally aren't ticklish usually have 1 or 2 ticklish spots. Or maybe there's a certain technique you have to use to bring out the ticklishness. I'd have to go for the challenge of Emma Watson and see what I could do.
I'd be more than happy to volunteer for a no-holds-barred tickle fight with Emma Watson. If she should indeed prove not to be ticklish, and I lose miserably, that's just the price I'll have to pay... .