So you need a media player and the right codecs to watch your anime right? Well here's some media players that you may have heard of, and are commonly used for our very purpose.
Media Player Classic - "MPC", often confused with Windows Media Player. Probably the best player you can get. Huge amount of options, incredibly basic with no forced codecs, and highly adaptable.
Video Lan Client - "VLC", the self contained player. Don't need anything external. Download this and it plays everything with INTERNAL codecs, that is, it relies on its own library of codecs iniside its folders, and ignores any codec packs you download. Becareful, as it often messes up subs made with specific codec packs in mind, etc.
The Core Media Player - "TCMP", a relatively reliable player that covers the basics of .mkv and .ogm files. Has been known to have conflicts with other players and their codecs. Still useful in many cases.
BS Player - A very reliable player that is preferred by many anime viewers. Handy, compact and fairly streamlined.
Zoom Player - A compact player with good capabilities. I have never personally used this, but I have not heard any noteworthy complaints about it.
Windows Media Player - "WMP", probably the most well known, as it comes standard with Windows. However, I don't recommend you stick with this. Eventually, you'll run across .mkv and .ogm files, or codecs it doesn't know how to read. And trying to adjust it isn't worth it.
MPlayer - Think MPC, but compatible with linux and MacOS. I may have forgotten it earlier, but it's worth taking a look at. Thanks to Volvo for the heads up.
Xine Player - Another quality player with a good track record and high reliability. Worth looking into. Thanks once again to Volvo.
Quintessential Player - A nice looking, reliable media player with good playback and lots of options. Although, like winamp, it's a music player first and an all around media player second, its still up to par.
FFDSHOW - Probably the most expansive package of codecs available, it is continuously updated to allow you to play the latest media files available online. They were some of the first to release an H.264 ready pack. If you don't know what I'm talking about, disregard that. With a pack like this, you won't need anything else. Sadly however... with a pack like this, there's no room for anything else. This pack will annihilate any other codecs you have by way of conflicts. Uninstall and remove any other codecs you are using. And be prepared to tweak your settings to stop all those weird things that start happening when you watch an episode, like sound distortion and video errors. If you were to put ffdshow on a computer that's just been wiped, it'd run perfectly. In any other situation, don't count on it.
The Combined Community Codec Pack - CCCP, by the folks at KAA, a noteworthy anime ripping group, is a sort of "for the community, by the community" take on the whole business of codec packs. This is, all in all, a very reliable pack of codecs that covers all the basics and the more recent stuff. Very worth your consideration.
The K-Lite Mega Codec Pack - K-Lite, is an old codec pack that has all the basics and includes a handle replacement set of codecs for quicktime and realplayer. Very very handy. This was my first codec pack, and at the time, it was absolutely perfect. Whether it's near as good now, with all the new formats out, I can't really guarantee.
Nimo's Codec Pack - Nimo's pack was one that you heard thrown out a lot when people talked about good codec packs, and generally it supports what you need, however I have not used this in ages, and cannot tell you whether that still applies now. But it was once extremely popular, and it may still be as reliable now as it was then.
The Tsunami Codec Pack - I cannot give any sort of description of this pack due to my never having touched it previously. However, it is one of the packs previously in heavy use.
Cole2k Media Codec Pack - Another quality media pack that includes
a plugin for Nero, both the Zoom and MPC media players and video and audio dubbing packs. Very expansive stuff.
Cold-Knight of the HolySentinels
123 Awesome St.
That One Place, Texas, U.S.
MORE TO BE ADDED AT A LATER DATE.