Enjoy programming AVR microcontrollers, but wish there was a better way to debug your programs than blinking lights? The best option is probably be to get a hardware debugging tool like the AVR Dragon, however it has a reasonably steep learning curve. An easier option might be to use the Simavr, a new software emulator for AVR chips. In addition to emulating the functionality of the AVR microcontrollers, it has a library that you can use to emulate peripherals, such as buttons or LED screens.
Simavr, an AVR microcontroller simulator