1. John Barrowman as Chiana/Farscape.
This was actually suggested to me by Marie but when she said it I could see how it might work really well. Both are irreverent, open to a multitude of experiences, cheeky, good looking and both possess an endearing core of sweetness. I think John Barrowman would have made an excellent he-Chiana.
2. Ben Browder as Madelyn "Maddie" Hayes from Moonlighting
No idea why she came to mind but I think that the main reason is the incredible chemistry she had with her screen partner in that show, which immediately made me think of the Browder/Black chemistry. Both blue-eyed and pretty stunning (for my taste of course), Ben Browder as Maddie Hayes could have made the role work really well.
3. Megan Mullally as Rygel/Farscape
I chose her mainly for the way she played Karen Walker in Will & Grace. Karen like Rygel was selfish, self-centred, sharp-tongued, greedy for drink (Rygel is greedy for food in a very similar way) and yet Megan Mullally played her in a way that, in spite of it all, made us like her thanks to rare flashes of generosity and kindness shining through. Dominar Rygel XVI was the same - he was a selfish brat but you just had to love him (not in small part due to the great voice work of Jonathan Hardy).