I really like the MD5 format, its really easy, simple and text based. Also has support for skeletal animations.
COLLADA is the other popular option these days, its supports the entire kitchen sink but from what I've heard its a nightmare to fully implement.
MD5 looks promising. COLLADA is interesting, being XML, since java has library support, but looks somewhat complex. Admittedly I only need to read a subset, so it's worth a bit more attention. I think I'll make or find a model in blender and then make a java view application for one of the above and see how I get on.