Many photographers skimp on tripods and I think that is a mistake. I see this when traveling all the time, and sometimes in my classes. You see an expensive digital SLR camera and lens on a low-priced tripod. Many photographers think nothing of spending hundreds of dollars for a lens, but complain about spending the same for a tripod.
Yet a good tripod can make or break the sharpness of any lens. In my Olympus gear, I have lenses that cost anywhere from $500 to $2000. To me, the cost of my tripod and head, about $1000, was a very important investment and worth every dollar. You can get good tripods for less, but the really low priced tripods are not worth the price. A cheap tripod that does not do its job well is too expensive.
I recommend a carbon fiber tripod for its light weight and a lightweight magnesium alloy head. In addition, carbon fiber is not as hard on the fingers when it is cold — metal tripods will sap the warmth and energy from your fingers. A quick release head helps make using a tripod easier.
Manfrotto and Gitzo are always good brands, both imported by Bogen. Manfrotto tripods are solid units that are a good value for their money. Gitzo tripods are expensive, but their fine construction is a pleasure to work with. Both manufacturers also make good tripod heads.
I use a Gitzo Mountaineer GT1540 tripod plus a BH-40 Really Right Stuff head. What is more important than the specific models are the reasons that I use this combination. I think you should look carefully at your needs for a tripod as this will affect which ones you use. I got this tripod for its compact size and light weight for travel - it easily collapses to suitcase size. Plus, the Really Right Stuff head is quite light, too. So in the field, I am not carrying more than a very few pounds of tripod and head. I also like the Really Right Stuff tripod mounting plates which allow for secure, quick-release of camera/lens.
That said, there are some new heads from Manfrotto and Gitzo that have come out in the past couple of years that I quite like and would easily consider them a challenge to the Really Right Stuff head. The Gitzo heads are very finely manufactured and a true pleasure to work with, while the Manfrotto heads offer a solid, great value for the budget-limited photographer.
If I did less travel, I would probably opt for a three-section leg tripod (mine is four), as they are just slightly sturdier and faster to set up (though my four-section legs are very sturdy) and a slightly heavier head. One thing that is quite nice for carbon-fiber tripods now is that you can tighten and loosen the knurled locking rings all at once and open and close legs, which is not possible with older styles (and some tripods on the market now - this is not a quality issue, but a convenience feature).
Bottom line for my tripod and head is that it is lightweight, compact and easily taken anywhere. You can have the sturdiest, most wonderful tripod in the world, but if you hate taking it with you, it is worthless. I have no problem making sure my tripod is always with me.
The photo seen here was taken in the Ancient Bristlecone National Forest near Big Pine, California, nearly 20 minutes after sunset, which meant a long exposure of many seconds. A tripod was a necessity.
Note: Rob Sheppard is a columnist for Outdoor Photographer magazine, an author of many photography books, and an instructor for BetterPhoto.com's photography school online. Rob's online photo courses include Impact in Your Photographs: The Wow Factor, The Magic of F-Stops: How to Choose the Right Aperture, and Successful Publication Photography.