Mulch!! Definitely mulch! We made the mistake of letting a landscaper put gravel over weed control fabric 15 years ago and have regretted it ever since. The gravel embeds in the soil and it is hard work to remove it, and the weeds grow right up through it.

Most people regret that they used weed control fabric PERIOD!

It depends upon where and what you are using it for.

I have a strip of ground immediately next to the house that nothing will grow in. It gets too much shade, no moisture and its compacted from construction. I didn't want mulch right next to my foundation, so I put in a strip of what we call "river rock". I put landscape fabric under the river rock, to keep the rock on top of and seperate from the soil. I do not plan on planting anything in this strip of rocks. Its simply to act as a soil cover, to keep dirt from splashing/blowing up on to the foundation.

But in most of my planting beds, I use primarly shredded wood chips (from a pallet disposal place) or shredded leaves for mulch. I do need to do an occaisional weeding and I re-apply mulch periodically as needed.

Its not so easy to re-apply rocks, and eventually they fill in with soil and grow weeds. I would stay away from rocks and fabric for planting beds. But rocks and fabric can play a role in the landscape, it just depends upon what your goals are.

Weed control fabric works best for under decks or under walkways. It does not work well for controlling weeds in flower or shrub beds.

So, assuming you are using it for pathways, I like stone screenings or stone dust best for a path as it compacts well, drains well and is not muddy. Use about 3-4 inches, compact well and it will last for a number of years before needing more dust added. Mulch on pathways gets tracked into the house and needs yearly replacement. Pea gravel is hard to walk on.

Gravel, or stone, is also a "mulch" which is defined as something put on soil to aid in weed suppression. So, as joepyeweed has already stated, what to use depends on what you want to do. If there are to be no plants gravel, or stone, might be a good choice although over time dust from the air and organic matter will accumulate in the spaces between the stones adn allow "weeds" to grow there. If where this will go will be planted then you want some kind of vegetative mulch so it will, in addition to suppressing "weed" growth, aiding in soil moisture retention, add organic matter to your soil.