Confetti is cheap- great, cleaning up is not so great.
#2 Flower Petals
Very pretty and versatile which is great however the cost can be not so great.
#3 Bird seed
If your outdoors you may not have to clean up- very great! Not so great is bird-seed hair or bird seed dust.
Pretty and traditional is great but the clean up? Not so great.
#5 Silly String
Very fun is great but silly string stuck to your clothing and in your hair- not so.
#6 Ribbon Wands
Great for photos and fun with no clean up but who will make them all?
#7 Fall Leaves
Fall leaves as confetti in Fall, great as it's natural, not so great if they're dirty...or buggy.
Great if your getting married in the evening, not so great for safety in a small or overcrowded space.
Makes for great photos, can not be great when burst over nice clothing.
#10 Balloon Releasing
Exciting and unique so great right? Not so great for the environment.