In that context, raise your hand is really the only one that's appropriate (in American English, at least). It's an expression that's used fairly consistently, and I can't think of any alternatives that wouldn't sound awkward to a native speaker.
Though it's not quite the same, there is a similar expression, using "show of hands." Usually, it's used when you're looking for a general count:
"Can I have a show of hands? How many of you did the reading?"
"Could I get a show of hands? Who wants to meet on Friday?"
"Give me a show of hands if you agree with me."
Hope that helps!