You will get lots of religeous arguments here about the merits of slides vs negatives. All of them are true. That being said, I use color negative materials. I believe they are more forgiving in difficult lighting situations, and are available over a wide speed range at neighborhood Jiffy-Marts. If indeed color saturation is not as good as some slide films, one can always cheat and crank it up in Photoshop. If indeed negatives are grainier, my end product goes to a computer screen so the point is usually moot. All color is illusion...