As icassel points out there are some critical factors to consider. 1. How much can you spend? 2. How tall do you need the tripod to be (ie if you're 5'1", then getting a tripod which extends to 72" might be a waste) and 3. How heavy is your gear?
1. Be prepared to spend $200 - 250 for a decent used Bogen, Manfrotto or Benbo with head. If you're buying new, expect more in the region of $350 - 500, and if you're really rich and can afford a set of carbon-fibre legs, you're north of $700.
2. Read the height spec' on each set of legs carefully. Ideally you want something that at less than full extension will put the eyepiece of the camera at your eye-height without you having to bend much, or at all.
3. Determine the weight of your heaviest body and lens combination, double it, and then add a little bit. Look for legs and heads that are rated for that weight. That will give you a reasonable assurance that it's not going to fall over in a light breeze.
(Bear in mind that all quality tripods come separately from the heads) Look for tripods which have reversible or tiltable centre columns (much more versatile) and legs which will open almost flat (to get down low).
I've used a Manfrotto 190Pro with a 488 ballhead as my 'travelling' tripod. Relatively light, quick to set up, and tough as hades.