Media Monkey is good as a free product, but I use J River Media Center, and although it is a paid program, it's awesome for not only organizing your music collection but also renaming files, making playlists (as well as random ones). And it's extremely fast! Avoid iTunes on Windows; it's a bloated piece of junk that almost seems purposely designed to run slow on Windows PCs.
J. River Media Center is the most complete and feature packed Music Manager/Library/Player out there. I've been using it for a few years now and I have never looked back. The library is lightning fast, even when you have thousands of files. It's library views are great and be customized to your heart's content. Support images and video but I only use it for music.
I also use it for playing music on other computers, tabltes or phones (it supports DLNA) and also a web interface. It has a full-screen interface like Windows Media Player but this feature needs a little bit more polishing because it can lag at times when browsing on your TV with a remote control.
It has awesome DSP options like 5.1 encoding, room correction, volume normalizing, etc. and can sync/transfer content to iPod/iPhone and Android or Windows Phone devices too.
It's worth every penny if you ask me.
For a free alternative, you can use MediaMonkey which has plenty of features. Another good one is MusicBee but I haven't use it in a while.