I'v seen Rouens, mallards and cayugas cross with Pekins. But, I don't know if I would say they looked awesome. Mostly, they kept the other parent's coloring, but kept more of a Peking body type.
Someone on BYC crossed a good quality chocolate runner with a Pekin and it looked pretty cool, I think.
I had a Muscovy drake that got to one of my Pekin ducks so I put 6 of those eggs under a broody chicken and 2 hatched. So far they look pretty strange because they have not fully feathered out but some of the feathers that have come in are barred.
My Mallard x Pekin duckling looked almost exactly like a black Swedish duckling
Here is a pic of his parents
Here he is with his mom
Here is a better pic
This him when he was little older
Unfortunately I never got to see what he would look like when he was fully grown b/c he passed away soon after these last pic was taken. He was so pretty