I can't tell you what's "best," but I can tell you what works for me. First, I have a Netgear 516 NAS, currently with 8 terabytes in RAID for redundancy. The NAS is important, both for expansion and for processor strength. Most NAS have pitifully underpowered processors. Shell out the extra cash to have a decent intel processor. This is important (for me, at least), because I also store my movies on there, and I have Plex Media Server installed, which will transcode the media to match what you are using. So it will transcode an MKV if you want to play it on your iPad, for example. It might also transcode a FLAC to play on an Apple product, since Apple does not support FLAC. You want Plex on the server rather than on a separate computer so that if you are away, you can access the Plex server without having a computer hooked up to it, running Plex and turned on. All of my music is in FLAC. It is lossless, and more efficient, size-wise. It does not natively play on iPads, iPhones and through iTunes, if that is an issue. If it is, use Apple Lossless, which is close to but not identical to the results of FLAC.
Second, you need some way to get it to your music system. I have a Marantz 8801 which conveniently has an ethernet port to connect it to the network and it will play music directly from the server (but not video). However, I use a Naim NDX DAC/Streamer, which is a far superior DAC to the Marantz and run the Ethernet cable to the NDX, and analog outputs to the Marantz. FYI, for movies etc., I use a KDLinks 720, which is a great little unit for accessing video (and 5.1 music FYI). The KDLinks will also play music too, but will allow you to play on the TV screen whatever album art or booklets you have stored with the album.
Third, you need some software to organize your collection. Naim has a free iPhone app that allows you to access your music, and displays album art and information when using a Naim streamer. Very nice. I typically use the Naim when listening to music at home, for highest quality. I also have Plex installed on the server, which is free and works great. Its ability to display album art is relatively limited to one cover at a time, although you can load multiple covers and switch between them. But it also organizes your video files, tv shows, pictures, whatever else you want it to, so as a media server, it works great. Plus, accessing your collection from anywhere with an internet connection is simple with the Plex app, so you can take your collection with you anywhere.
There are a lot of different solutions, but mine takes care of everything!
