I thought your post did a good job of giving the audience a well rounded variety of examples. Excellent work!
the font on the celebrities header takes away from the professional look there, area 51 ones are pretty good
I like the banners alot but I think you should put more emphasis on your text. That would make the final product stand out more. Maybe some type of texture, gradient, filter effect etc.
i mite come across as a bad person here. but its the only way to teach use better fonts. most of those are just wrong. dont use dropshadow so much on text. and when you do try not use it when its blurryish. and for the banners. am never keen on just pictures all meshed together and some text put over them. *hides*