Often times, a door is the unsung hero of the house. Other than the front door, which people tend to moon over a little more, the interior doors of your house just usually end up being whatever you can get cheapest off the shelf at the Home Despot.
That's why I love the design your door tool from Trustile Doors.
First of all, you can just play on that thing for hours... picking out flat panel, raised panel, 7 panel, ogee trim, bevel trim, rounded top, glazing, resin inserts, whatever. It allows you to see how much impact a well designed door can have.
On top of that, they just make a quality paint grade MDF door (in addition to the solid wood ones, but solid wood doors should only be used in hunting cabins at the lake or period dramas set in the 1980s or the 1890s.) And they have specialty art glass from Bendheim and Resin inserts from 3form as part of their standard offerings.