Its a tough one, I would like to say OS4, I am a OS4 fan and plan to get a OS4 machine this year, but I think that maybe it would be better to support Aros simple because if a company fails or some closed source parts can no longer be used then development can run to a halt, that problem doesn't effect Aros, plus its very nature means anyone can come along and design their view of how an ng AmigaOS should be and release it, its been ported to a number of devices and is hardware free so no one can say 86x VS PPC crap, its free so no complaints about price. Plus I dont like saying this but the key Aros users and supporter are more professional than both Hyperion and MorphOS team and very little do I see their thread debunked to moan about either OS4 or MorphOS, and this whole daft Red vs Blue stuff. Plus I love the phase “No schedule 'n' and Rocking” this is why I am a OS4 and Aros supporter.