For BL.. This pairing right here is the example of side couple that is really good!! Even better than the main...
He Xian x Mo Guan Shan from 19 days
This couple is on par with the main couple. They even got a sequel of their own which speaks volume of the pairing.
Hirano x Kagiura from Hirano to Kagiura
... and lastly... this my personal favor......
