My favorite format among the "poor man's" (non 3ds max/maya software) is Milkshape 3d. It imports/exports faithfully between them all, as far as I've experienced. Milkshape (of course), Blender, Fragmotion, and Ultimate Unwrap all do it with animations intact. One thing, when loading in this format into Blender, though, is that it takes a LONG time. No, Blender didn't crash, just go make some coffee or tea, have a cup, go check the mail, etc. If you can get it into Blender, things will be fine as long as you're using 2.69. I know some people have had some success with newer versions, but I still stick with 2.69, as I've seen more people with issues than successes. I still have 2.76 installed but I use it for solid geometry for 3D printing.
MAME Cab PC: i7 4770@3.4Ghz (passmark 9945), 12GB RAM, Win 10/64, GeForce GTX645 (passmark 1898); Shiny new laptop: i7 4800MQ@2.7Ghz (passmark 8586), 16GB RAM, Win 10/64, GeForce GTX870M (passmark 3598); Old laptop: i5@2.3Ghz, 8GB RAM, Win 7/64, Intel 3000 graphics