Good Example 1
I think Google Earth did very good job developing their user interface.
The purpose of this application is to act as a search tool which users use to look for directions or just locate different places by categories
I think the interface is very good because it is intuitive. When a user asks for directions their way is highlighted and the user has the option of "driving" to the location by pressing play on the direction menu.
It also has a Places submenu, which is a user modified area and allows them to quickly locate the places they've bookmarked.
If someone wants to see the the area around a specific location, they can just click the mouse and move the whole map around. This function might not be intuitive at the beginning, but once the users are used to the interface, it is very helpful.
The Layer submenu allows the users to select places of interest by categories and people are able to see those highlighted places right away.
Good Example 2
Abother example of a good user interface is the Roxio CD Creator. It has very Windows like feel, so the user has the same experience as if they are searching through the files on their computer. The interface also provides drag and drop function and selection of multiple files.
The bar at the bottom informs the user how much space they have left on their CD so they can plan in advance what they want to burn on the CD.
Another good aspect about the interface is that it allows the users to preview the files they are allowed to burn, so even if they forgot the exact names of the files the need, they can allways check them whithout leaving the application.

Bad Example 1
I will use my TV as an example. Its interface is extremely confusing. For example if I want to search for channels it allows me to search automatically or add/delete a channel, however when I click on the add/delete in only deletes the channels. Another aspect of the interface which is even worse is that some of the functions like sleep or mute (some of the most common) are available only through the remote control and since I recently moved and forgot my remote at my previous place, I am unable to use most of the functions. When I go to the Caption sumenu, it doesn't give me all of the available options like the other submenus, but I have to keep clicking through all the options. Sometimes I miss the option I want and I have to go through all the options again in order to select the needed one.
Bad Example 2
Another bad interface is actually the Usernomics website. It has all of its links as seperate buttons which first of all is overwhelming for the users to go through all of them and second they look like links to submenus that will lead to more options, but once clicked the website just displays different information on the same page. It has even a seperate button for adding the website to the Favorites of the user's browser and this option is available to the user even without this button. The buttons are not grouped in any category so it can be difficult for the user to find the button they need even if they are used to the layout of the website.