1) That is disrespectful to Tina Fey.
2) Prepared to be disappointed. I am not that funny.
3) What if I tell you I am? (Then you might decide I don't really look like her at all.)
4) Um, thank you...if you are a fan of her looks. If you are merely a fan of her work, see #2.
5) Does that get me any free stuff?
6) Ugh! Does that mean I look like Sarah Palin?
It just seems like more of a conversation ender, than a starter. Are we then obliged to try to think of someone this stranger looks like?
Sometimes the person you supposedly look like is not a celebrity, but just some generic random stranger. This doesn't even allow you the chance to come to your own conclusion about any possible similarities. There are also the cases of mistaken identity, as an unfamiliar face is smiling broadly at you until you get close enough for them to realize their error. Well, now that person is most likely about to be disappointed! (And you are disappointed to find that you no longer warrant a smile.) I like when the tone is accusatory...as if I have NO idea who I am. "Do you have a twin sister?" I'm pretty sure I'd have thought to mention it if I did!
By the way, "You look familiar" is acceptable, as then there is a chance that you aren't talking to a stranger. Just to clarify, looking LIKE someone who you've already established you are not does not obligate you to further discussion.
I am equally unenthused when being told I remind someone of so-and-so. Here are my thought patterns then:"Oh really, does cousin Matilda find your conversation points dull as well?"; "Is that the person you were complaining about 2 minutes ago? I'm touched."
Maybe it's just me...afterall, I'm just me!