external mic for Sony HDR-XR260VE

Step 2: Define your requirements.

There is no single best mic for all applications.

Mics can cost from $10 to $10,000. There are mono and stereo mics. Shotgun mics are directional and are typically mono like the decent and affordable Audio Technica ATR6550 or NRG Research SA-568. There are stereo mics like the RODE Stereo mic. There are handheld, dynamic, mics (mono) and clip-on lavaliere mics... Many can be wired or wireless. Audio Technica, Shure, Sennheiser, NRG Research, and many others have a range of mics with different capabilities and prices.

Your Sony HDR-XR260VE has a 1/8" (3.5mm) stereo audio input. If you choose to use mics with XLR connectors, then you'll need an XLR adapter (like those from juicedLink or BeachTek - among others). Since the XR260 does not have very granular audio control, use of these sorts of adapters is useful because their audio gain control knobs can provide the desired control. And usually, XLR mics are "better" (but not always).

Usually, the "compatibility" is about the impedance of the mic - so mics designed for use with a computer may not match the camcorder's requirements. A condenser mic that needs external phantom power (and has no place to hold a battery) can use an adapter but USB mic just won't work.

If you want to use an XLR mic with the 1/8" connector, the aforementioned adapter would be needed. I would not call this a "compatibility" issue. If you use an XLR mic that needs phantom power (like many good shotgun mics or other condenser mics), then be sure the XLR adapter has the ability to provide phantom power.

The Sony HDR-XR260VE has no accessory shoe so mounting the mic to the camcorder means using a camera bracket like
http://www.bhphotovideo.com/c/product/734090-REG/Vello_CB_500_CB_500_Dual_Shoe_Bracket.html
helps. Because it has two accessory shoes, one can be used to mount the mic and the other can be used for a video light.

The USB port on your camcorder will not support a USB mic. That port is used for transferring data files (the captured video and still images) only and cannot be used as an "audio-in" port.

As for defining the requirements... watch the news. You will typically see three types of mics. Clip-on, wired lavalieres for the studio talking heads, handheld dynamic mics (many times wireless) for the field reports and shotgun mics in the field when some sort of press conference is going on and the dynamic mics aren't all on the podium mic stand.

How you use the mic and what sort of audio you expect will determine which mic should be used... and I did not cover boundary mics, or other specialized mics, like throat, headset/boom, and others.