Collada plugins for Max/Maya are available from several parties.

FCollada

FCollada plugin (3.05C) is no longer developed, but it is probably still the best option.

Significant plugin errors:

It may export inverted opacity. This is problem of Collada 1.4.1 format, solved in 1.5.0 by addition of RGB_ONE and A_ZERO modes. FCollada will always support only 1.4.1, so this problem will stay.

OpenCollada

OpenCollada plugin has bright future, it is under development, aiming to replace FCollada, and it is already very close.

Significant plugin errors:

Everything has specular reflection This is the only problem that stops us from recommending OpenCollada over FCollada.
It may export inverted opacity. This is problem of Collada 1.4.1 format, solved in 1.5.0 by addition of RGB_ONE and A_ZERO modes. OpenCollada exports to 1.4.1, but developers promise option to export to Collada 1.5.0. Right now, version can be changed in plugin source code, by passing COLLADA_1_5_0 as third parameter to the mStreamWriter ctor at http://code.google.com/p/opencollada/source/browse/trunk/COLLADAMax/src/COLLADAMaxDocumentExporter.cpp#58
Other less significant problems are listed in issue tracker

NexGen

Avoid. This is old name of OpenCollada plugin, therefore NexGen plugin is less developed than OpenCollada.

Autodesk Collada

Avoid. Max/Maya may include Collada support out of the box. We have never seen it doing its job well.

Coherency test

We support Collada 1.4.1 and 1.5.0 as they are specified by Khronos group. We try very hard to support also broken Collada files produced by broken third party programs. But everything has its limits. To test correctness of your Collada documents, use Collada Coherency Test.