There is much discussion about cypress mulch vs. bark mulch. Both have advantages and disadvantages.
Cypress Mulch: Advantages and Disadvantages
Many people boycott using cypress mulch because it is obtained from wetlands such as those in Florida. This is a non-sustainable source and it is quickly being depleted. Some mulch manufacturers claim to be using only waste cypress however. Another disadvantage to cypress mulch really is a point of view, and in some cases can be called an advantage. It decomposes at a very slow rate, so its not recommended to amend soils. Of course, this would make it ideal for pathways and in areas where you don't want to constantly be replacing it.
Bark Mulch: Advantages and Disadvantages
Bark mulch may be composed from a variety of hardwoods from naturally sustainable sources and is available in chunks or shredded form. As a rule bark mulch is less expensive per square yard to lay down than cypress mulch. Bark mulch will decompose quickly and is a good amendment to loosen soils. It is usually less expensive than other types of mulch.
A disadvantage of bark mulch that it can float away and into street gutters and all over your sidewalks and driveway in a hard rain or heavy watering.