Since I am just a casual camcorder user (actually the HD2000 is not even mine, it belongs to my wife), I do not have much accessories for it. The first accessory that I bought together with the HD2000 is a UV filter. This is for protecting the lens more than anything else from greasy fingers, dirt and the outside world. When you need to, it is much easier to clean the filter than the lens itself. The one that I bought is Kenko made but the more well-known and popular (and so more costly) brand is Hoya. I suppose any reasonable brand will do as it is just a protective piece of glass but purists may disagree. The only important point to note is that the diameter of the thread on the lens of the HD2000 is 40.5mm so you must get the correct size filter. The one on the Sanyo FH1 is slightly smaller at 37.0mm so make sure you pick the right size.
The only other accessories that I have is a spare battery and a battery charger. Thought the battery itself can last reasonably long for some normal shooting, it may not be enough if you are on holiday where you tend to be trigger happy. Nothing can be worse than your battery running out at a crucial moment. The original Sanyo replacement battery for the HD2000 or FH1 is model DB L50. I do not know why, but the Kodak battery model KLIC 5001 is exactly the same item and can be used perfectly as a replacement battery if you want a branded one and this could be cheaper and more easily available than the Sanyo.
Of course there are many nameless replacement batteries, especially those from China and these are much cheaper than the Kodak or Sanyo battery. Buying such nameless battery can be a hit or a miss and there are some horror stories around. But there are also many satisfied customers, for after all so many items are now made in China, most probably the Sanyo and the Kodak as well.
The same goes for the charger. The original Sanyo charger is model VAR-L50 and this is the one to go for if you want peace of mind and don't mind spending a bit more. The cheaper alternative is to go for those unbranded chargers which can do the job equally well but don't know for how long. Do a search on Amazon or other reliable sellers and pick one with the price that suits you and you should be OK. But the choice is yours if you are more comfortable with the branded originals.
Being a cheapskate, I went for a Chinese replacement battery for Kodak KLIC 5001 and a nameless charger. I was very apprehensive in the beginning, but after going through a few charging cycles, everything was OK; touch wood! Initially, the idea was that the replacement battery will only be charged with the charger and the original battery will only be charged in the camcorder via the docking station to protect the innocents. After a while, anything goes and they all seem to be happy with each other. So much for mixed marriages.
And so they live happily ever after. Hopefully!