I think Pizza Hut has a really good logo.  If you haven’t seen it, it looks like this:

For the longest time, I just sat looking at the logo trying to figure out what I liked about it.  Nothing really jumped out at me, I just knew that I liked it.  When I think about it, though, I think I like it because it’s so stylized.  It looks like someone drew the logo with a fat Sharpie or something.  I think that’s really cool because it gives it a friendlier feel.  It doesn’t seem so uptight and commercialized.  That’s really why I like it so much.

As for effectiveness, I think the stylization works for that, too.  It probably gives other people the sense of friendliness that it gives me.  Also, the logo includes their very distinctive, signature red roof.  This is really effective because if someone can’t remember the actual name of the pizza place but they remember the logo has a red roof, they’ll be able to figure out which pizza place it is they want to go to because of the red roof.  I think it’s a really good marketing tool to put the red roof on their building and on their their logo.