I have this all the time when people ask me what my favorite movie or favorite dish is.
I like a lot of the movies I've seen, but I just can't pick some favorite, and I never think about which movie would be my favorite, it seems impossible to compare. Often enough when I couldn't pick a favorite, people thought I was lying about having seen many movies or they thought I was too lazy to answer or something. To counter this I checked IMDb though, and my answer to this question is The Shawshank Redemption these days. Rather than frowning, people agree.
I don't have a favorite dish though, this is where I fall back into my old habit of just mentioning lots of different international kitchens that I like in general 