I would have to say the first one and the best purchase I have ever made would be the cotton carrier vest. This has been a lifesaver for me because I can easily strap a camera body with a 600 mm prime and another camera body on the side holster and walk for 3 to 5 miles with no issues. The second would be the series 4 gitzo monopod which I use all the time. The third would be heated gloves for winter time. These are a must for me because I have so much nerve damage in my hands that once my hands get cold I am done.