A camera! Obviously. But what kind(s)? I shoot Nikon, not because I think it's better than any other brand but simply because it feels the best in my hand. I own both the Nikon D3000 and the newer Nikon D7100. Both of these cameras are crop DX sensor cameras (APS-C). Nikon has recently introduced a camera specifically geared towards the astrophotographer, the Nikon D810A. I am very anxious to test one of these out but they are currently obnoxiously expensive. Renting one for a while may be the way to go!
I have a 18-55mm 'kit' lens, a Tokina 11-16mm Ultrawide lens, Nikkor 55-300mm lens, and the classic plastic, nifty fifty Nikkor 50mm f/1.8G. I also have a macro reverse ring kit that changes my 18-55mm lens into an inexpensive macro solution. Anyone looking to try out macro photography without the macro price should seriously consider this kit - typically around $30.00. I am currently saving up for the Nikkor 70-200mm bad-ass. I have a few specialty filters for my lenses as well as a triggertrap for some sweet and unique pictures.
I simply swear by the Yongnuo 560 III flash - so much so that I own 4 of them. I think this version may be discontinued because of the release of the IV version. I would not hesitate buying the IV version should I need additional flashes. They are simply remarkable and a fraction of the cost of a comparable Nikon flash. I also have the Yongnuo YN560-TX to remotely change power levels and trigger the flashes.
I have several umbrellas, soft boxes, light stands, and a backdrop system. I also have a Vanguard Ultra Pro 263 AT tripod. A solid and sturdy tripod is a MUST for long shutter speed photography.
I am a firm believer that the price of your equipment DOES NOT equate to better pictures. Some of my best pictures were taken with my entry level Nikon D3000 with the cheapest kit lens sold. There are absolutely times when having specialized equipment is a necessity (like astrophotography). A skilled photographer can take a far better and more appealing picture with a cheap camera than a novice can take with the top of the line camera. The camera does not make a good photographer. Understanding LIGHT and how to manipulate it is the key to great photography! In some ways, I went about photography all backwards. I started with the most challenging scenario - astrophotography, then moved to flash photography, then to natural light photography. But if forced me to understand light and how to change it with ISO, aperture, and speed settings to achieve the image I want.
Far more interesting blog posts to come. Feel free to leave a comment or competing viewpoint.
Keep the interesting parts of life in focus.