Lineatre makes some seriously ornate bathroom furnishings. Their upholstered toilet seat pretty much sums up their esthetic. We're not talking Kushy Tushy here. These seats are 'punctuated with deep, diamante buttons'. Available in 'glamorous gold' or 'gracious white'.
If you're worried that your upholstered seat would look out of place in your bathroom, you could put in a coordinating, upholstered bathtub.