Is there anything you can't get?
Just traded a Deino for a Type-Null. Trying another Deino for a Cosmog now.
Post your craziest trade results.
If you try enough times you tend to get what you want
I have dozens of hacked Tapus that people have sent me through wonder trading, and Deino is the sort of thing I would struggle to get, so if I wanted to breed Hydreigon, I would make that trade.
I have almost a full box of Dialga on Pearl that I almost exclusively traded female Combee holding rare berries for.