Speedlites

Most DSLR's come with a popup flash, in fact just about all cameras have a built in flash to help with providing light to illuminate the subject. Unfortunately the built in flash rarely ever assists in producing good light. This coupled with its short range and its battery draining systems make it a last resort choice. My first speedlite was an aftermarket brand with only manual controls. I had to adjust the flash output after the first shot if it was too high or low. Aside from this quality it was an ok speedlite. However upon purchasing a proper Canon 430 EXII I realized the advantages of a good speedlite. For starters this had TTL (Through The Lens). Everything is done automatically for you. 

This feature was a huge help to me being a beginner and not fully understanding how to adjust the power and other settings. In hindsight however using the speedlite manually was becoming easier the more it was used. Canon & Nikon all have excellent speedlite options from base models to expensive ones. Also there are some aftermarket manufacturers that supply speedlites that come very close to meeting the quality of Canon & Nikon. If at all possible when purchasing a speedlite acquire one that has TTL but also supports connection to an external battery pack. This will reduce the number of battery changes needed especially during a crucial moment.