You know me, I'm a fallen guy ;)

I can only agree with you. Fallen is an incredible campaign, much better than all the official ones together. I would mention the dedicated music, which is absolutely epic and immersive (cuz sometimes we don’t pay attention to this important part of the environment of a game). The conception and design are completely outstanding, with huge environments and beautiful and terrible landscapes (you can feel in hell and heaven simultaneously). The creativity of the designer is unlimited. Admirable lighting. Along the levels u can find traps, lots of different mechanisms, lots of ladders placed on panic precipices, canyons, caves, surrealistic and incredible towers high architecture’s level design, surprises, there is everything and more. All together with a good spread of supplies, a good amount of throwables, good balance between tank and horde events (except in the swimming pool and in the final of the devil’s ramp). Enough ammo and medkits but taking a lot of care in several levels. Of course, all these comments refer to playing in expert mode, which is the unique level that we “know”^^).
But other campaigns in this list (and out of it) are in the same level: for example Dead Before Dawn or Death Aboard, One 4 Nine and Night Terror; all of them are incredible campaigns much better than the official ones that deserve to be taken in consideration and to vote and comment them. So: come on!

Silent Hill and campaigns by ROMBU[www.gamemaps.com]. I like hard extreme and atmosphere in campaigns and these guys can do it.

Agree with Silent Hill, one of the best customs for l4d (although I don't like mazes and puzzles). but about rombu, he just makes adaptations of existing maps. What we need is creativity.

For me it's fallen, for its difficulty, the music and the fucking final grrrr

Dead Aboard is really nice (that one I played)