Well, VLC is helpful for at least 2 things, imho .....
First, it plays almost any existing types of codecs (with few exceptions for the weirdest types)
Second,
it reject to execute the executable content embedded in the hidden data tracks of ASF, WMV and MOV filetypes, and, trust me, it's not a feature to underestimate ..... with the same easyness that a "tricked" WMV file can open a webpage, send your ID and file title to page owner, and ask you to buy a license for see the file, it can open a page in background, download a virus, and install it without you notice anything, if you embed the right executables in the video file .....
So, as personal suggestion, use the player that you prefer for the WELL KNOWN and TRUSTED files that you have, but use VLC for anything you downloaded that is not a pure, plain AVI with no addon tracks ..... and just for be sure, also for them, when you check unknown videos ..... i think the proverb is "always better safe than sorry", right ?