Irrlicht Engine

From this list of animated objects supported by Irrlicht, which one would be the best if I'm working with Blender?

Animated objects:

B3D files (.b3d, r, skeleton)
Microsoft DirectX (.x, r) (binary & text, skeleton)
Milkshape (.ms3d, r, skeleton)
Quake 3 models (.md3, r, morph)
Quake 2 models (.md2, r, morph)

Right now (in Blender 2.5 versions) I've read from others using .X is probably the best solution. But that might change over time (especially when the new Blender script interface for exporting is finished).

You best create some test-model which has all the features you need and export it in as many formats as possible (might be just .X right now...). Then load it into the Irrlicht meshviewer and check which works best.

I'd be VERY tempted to say... write your own blender format reader.
But yeh .x is the best and the irrBlend exporter is even better