If you want easy, use windows
No, really, I hate myself for saying it, but if you want something that 'just work's', then it's not linux. Nore Vista for that matter
You could do a plugin that wraps other plugins, assign priorities, and then pick it, but it's not currently there. There is an SDL plugin around, but I've no idea how up to date it is. There is an AWT plugin, but obviously thats only mouse and keyboard. You can add the AWT plugin so it's always there, but you will then get mouse and keyboard devices twice if other plugins are working. You could parse the controller names so you know if it's an AWT device though.
Even Ubuntu, does not provide even read access to /dev/input/event* devices by default, so system config needs to be changed to read them directly.
If you wish to do an X or SWT plugin, feel free
Right now though, most users running linux, are capable of changing a few permissions. It's a pain, but unfortunatly, thems the breaks.
I'm not sure what oddlabs do about this? Elias?
Certainly needs some further thought.