The contest that i really like and i think very organized and have done it right is Marcus big party it's about he's alexa ranking and it only happens once for a long time -- but for some other blogs i experienced they approached me and i said yes i would like to sponsor this and that etc...then they replied okay i will book you and the next thing i know they sent me another message asking if i want to be one of the sponsor from the same blog so i did not replied anymore because i got it this is one of those contest that is not organized and just i don't feel right about and i received a lot of message from other blog contest and so i ignor them because i am not happy of to many contest anymore.
If you run a contest make sure that you pull it right, start it right and make sure that your contest is unique. One contest that i really like is Julians Library contest, she run it perfectly the top commenter from all of her blog will win $100 the second commenter will win $____ and so on... another constest that i like is amanda's competition from bloggerbuster.com, her method is unique and very well thought... there might be other bloggers that worth mentioning but this are just a sample. I am glad that the Big Contest Mania is over or shall i say at least it slow down a little bit, have not seen much about it.
I am sure that it is not just me who is sick of reading about contest, i don't get sick if it is unique. If you are thinking to run a contest think of them many times, ask yourself if who have done it if someone have done it already think of something else, something unique so that it's not sickening.