Whoa...this could get people fired up! There are some fiercely loyal riders out there when pedals, saddles and most components are mentioned. I won't go into the Campy vs. Shimano debate.
I haven't tried every pedal out there but I have had luck with Ritcheys and most Shimano spd pedals. I'm still looking to try the current darlings in the pedal category, the eggbeaters and the Time ATAC's. They seem to have the fewest cons.
Listen to the reviews here and also try this site
http://www.mtbr.com/reviews/pedal/
user reviews of almost every pedal out there.
Good luck!