Here is a great hat that I love to make. Credit goes to Catherine Lindsay who designed it. I found her pattern at http://www.crochetpatterncentral.com/. She has tons of patterns posted there that I love.
Anyway I find this hat very easy to work up and it looks awesome as a one or two toned hat. It may be hard to see in the photo but it actually has I bit of ribbing down the upper half of the hat. This gives it a unique look.
I have made lots of these as they have a great finished shape that flatters a lot of faces.
If you crochet and want to see more patterns I encourage you to check out the above website and also the designers website which I believe is http://www.yarncat.com/.