I always wonder how changing "Favorite" to "Like" would affect the frequency of the action on Twitter. To say something is your favorite is kind of extreme, right? - you can like lots of things but you only have one favorite. Interesting point you make though, because in an argument you'd be more likely to use a "favorite" to select the better stance.
Disclaimer: I'm a terrible Twitter user, and still trying to figure out what I'm doing.