4, 5, 2, 3, 6, 7, 8, 9 for the originals. 1 is pointless, there's no reason to watch it. Put up the youtube video of the Maul/Kenobi/Qui'gon fight scene and that's all you need. Then watch R1 and Solo at your leisure later.
If you really want to put R1 and Solo into the viewing order, then do it like this:
Solo, R1, 4, 5, 2, 3, 6, 7, 8, 9.
If you REALLY want to watch all of them, then you can put 1 between 5 and 2, but trust me, you miss nothing.