Lacking a Targaryen faction, i'm going to do the next best thing.
I'm going to take control of Stannis, marry Shireen to a Velaryon, and have all other generals killed.
Then; with a Velaryon as Lord of Tides, Master of Dragonstone and Driftmark at the head of what remains of Stannis' meager armies, he'll set about conquering the whole of the Seven Kingdoms like another Valyrian did hundreds of years ago - but without the help of Melisandre's magic or the Dragons of 'Aegon the Conqueror'.
Heck, I might attempt this in the Enhanced and try posting it as an AAR, but the bug would probably keep me from conquering all of Westeros. What do you guys think?