The one thing I've been fooling with is my music collection. I initially used Windows Media Player by default but then have been using iTunes almost exclusively. It's easy to use and fairly intuitive to use. Meaning you can use it more quickly without fiddling with it. I basically use it to rip CD's and listen to music with. I'm not an audiophile nut so fancy settings aren't necessary.
For those that need a little more Media Monkey may be the answer for you. I downloaded it and tried it out for a bit. It's has fairly simple interface, very much a classic windows look though I believe they have different skins. The one thing that's nice is that it categorizes each song in more detail. At least that's my initial impression. It takes a little getting used to after using iTunes for so long. Give it a try if your looking for something a little more in depth or just want to try something different.