Luckily, there are apps and workarounds so your Android phone can open most audio, video, image, and Office file formats you throw at it. Being able to playback a myriad of file formats is good because not all file formats are created equal. RAW images, for example, tend to be of higher quality than standard .JPEGs. And .MKV files can play videos with subtitles--helpful if you are hard of hearing, watching a foreign film, or stuck on an airplane with crummy headphones.
Also, by making your phone accept a more diverse number of file formats, you can save yourself the hassle in converting your media files into (more often than not) inferior and more common file types that aren't as good at reproducing hi-fidelity music, saving storage space, and displaying crystal clear images.
Audio
The default Android media player is very picky about what it accepts if you try to load it with anything other than .MP3s. For a better audio experience, look no further than the PowerAmp Music Player. The list of formats that PowerAmp can play includes .MP3 (of course), .MP4, .M4A, .ALAC, .OGG, .WMA, .FLAC, .WAV, .APE, .WV, and .TTA. Besides accepting a wide variety of audio formats, PowerAmp is customizable with several themes and comes with a handful of widgets to choose from. PowerAmp costs $5 (~ Rs. 230) for the full version, though there is a free 15-day trial as well so you can try it out before you buy.
If you don't feel like spending $5 (~ Rs. 230) on an app, you can also try out Mortplayer Music. Mortplayer (free) can handle all the same formats that PowerAmp can, though the interface is not as clean as the one in PowerAmp and it cannot play .FLAC files on all devices.Office Documents
While Windows Phone 7 phones may be the kings in handling Office documents, Android also can juggle work documents (Word, Excel, PowerPoint, and Adobe) with ease. All Android devices by default can view Office documents, but you will need a separate app in order to edit and create new ones. There are quite a few mobile office apps to choose from; it really boils down to what features you want.
