my fav type of advertising is guerrilla advertising. i just cant get over how cool transforming a regular environment into an advertisement, without being too pervasive, is. i personally find this type of advertising to be more effective because people find it interesting and actually want to see it and then later share it. pretty awesome...i hope to be able to do this type of advertising when im all grown up. here's a few of my favs...
ad for portable playstation. concept being that you can transfrom any environment into your game.
this is an ad for a british version of bleach and used existing street stains and put clothing around it to show their bleach could get the stain out.
amnesty ad promoting awareness of unfair punishments using the sewer as jail bars.
spiderman 2 ad using a urinal where only spiderman could get to to promote the movie.
awesome mcdonalds ambient ad using the light pole to look like pouring coffee. Mcdonalds has actually had quite a few pretty cool ambient ads out lately.