Regarding codec packs, shark007 is an excellent codec package that is superior to all the others. CCCP, K-lite, all do horrible stuff to your directshow and media foundation. However, shark007, as far as I know, is also a person who posts on sevenforums. His codec packs do not mess up with any of the windows 7 media foundation files. He regularly updates his package nearly every one and half week. I suggested this package because it is the only pack that I found to be user friendly and fast. He has 64 bit components and even includes a quick way to make 64 bit media player default.
I can understand where your suspicion of codec packs come from, however, shark007 is an exception.
Also, regarding VLC, is it not true that the extra ram and cpu is indicative of the quality of the program? A well-made program will arguably
take less cpu because of an optimized configuration, and the same for the amount of RAM used. However, if you play an H.264 file using windows media player incorporating the windows media foundation, you shall see that the program regularly uses around 80 megs of ram, but the cpu usage hovers around 2 to 3 percent. It is an amazing display yet it is completely true. You should try it for yourself.
Just my experience, because VLC just doesn't seem as graphic or user friendly as the familiar windows media player, that's all, (I find the interface horrible...but that is only my opinion ^^) I hope you didn't feel like I insulted you or anything.
Note: Windows media center is a 64 bit program. Thus, to add codecs to windows media center, you need 64 bit codecs.