I've found that IGES is the most useful cross-platform, cross-program file format. I'm currently working on finding a way to convert my Polygon mesh to NURBS in a format that won't create too many points when exporting in the IGES format.
AFAIK my version of Maya can export objects into the following formats:
mayaAscii and mayaBinary, move, mentalRay, animExport, FBX, DXF_XBF, OpenFlight, GE2, IGES, aliasWire, OBJ, iv2, RIB, rtg and vrml2