According to the Inception Wiki, we're both right.
> One method used to awaken from a dream within a dream is called a "kick", which is the sensation of falling, hitting water, or a sharp jolt that can startle the sleeper awake.
Although I still think it's terribly inconsistent, if the details matter. There's too many different kicks with too many subtle differences and similarity for me to go into in a reasonable-length post.