Should you choose RAW or JPEG? It's one of the most controversial debates in digital photography, so let's start with some facts.
RAW files are favored by many professionals, because they can be edited without experiencing the loss in quality of other file formats. They also capture more dynamic range, more information... the list goes on. However, RAW files aren't accepted by many computer programs, and they use up a massive amount of data. They also look flat and bland without editing. This is where JPEG comes in. Through smaller file sizes and in-camera editing, it's managed to become the file format of choice for many casual photographers. However, if you're a more experienced photographer, the choice is surprisingly hard.
Landscape/Portrait
For most genres of photography, the RAW file format is a must. It'll give you more freedom in editing, allow you to recover poorly exposed shots, and broaden your creative horizons. If you favor convenience over quality, try shooting in RAW + JPEG - it'll give you a chance to explore the faster JPEG format alongside the superior quality of RAW.
Sports/Wildlife
There's one genre where JPEG is preferred by the pros - sports photography. The speed of high-end sports cameras like the Canon EOS 1DX or Sony a9 means that the camera's processing chip can't handle the data of RAW files for long periods if shooting - and that's before you start uploading thousands of photos to your computer for editing.