One of the easier ways to do this is to look at the default wallpapers that would have come preloaded with the phone.
The Droid Incredible is preloaded with the HTC Sense user interface, whereas the Motorola Droid X has MOTOBLUR 2.
This touchscreen-based device runs Google Android and comes preloaded with Bing Search, VZ Navigator, a 3.2-megapixel camera, Facebook, Twitter, and speaker-indepedent voice commands and voice-activiated dialing.
The simplest kit to use is the Ana-kit, which contains a sterile syringe preloaded with two doses of epinephrine with a stop between.
Apple TV preloaded movies aren't all that common thanks to the complexities of the copyright laws but retailers have found ways through them.