TAudioConverter, a graphical front end for state-of-the-art audio codecs, is now my go-to tool for converting files and ripping audio from video files. It's fast and comprehensive, has a nicer interface than my previous favorite fre:ac, and doesn't attempt to install extra stuff as Freemake's Audio Converter does. Freemake is suitable for those who don't understand audio formats...but for those who do, TAudioConverter is what you want.
Besides being prettier and easier to configure, TAudioConverter also handles 32-bit files (with codecs that understand 32-bits, such as LAME MP3), while fre:ac does not. That alone was enough to make me switch, since often I record at 96kHz/32-bits. But it is also the only conversion tool I'm aware of that supports the Opus format, which is the will-always-be-free codec for HTML5.
TAudioConverter also loads and converts all the flavors of AAC (including Nero), AC3, MP3, MC3, Ogg, and WMA. Lossless codec support includes ALAC, FLAC, Monkey's Audio, TAK and TTA. There's WAV and AIFF as well. It doesn't output to APE, Windows lossless or Apple lossless output, but the program does read and convert all three to other formats.
Some codecs don't support all frequencies, the full range of bit depths, or channels beyond stereo. For instance, you can't output 7.1 surround to MP3, but you can to AC3. This is not a limitation of TAudioConverter, but the codecs being used.
TAudioConverter puts everything at your fingertips, makes it easy to choose an output format, does batch conversions (threaded so it can handle multiple files simultaneously), and lets you edit tags. However, you're limited to performer, album, genre (there's no helpful list), album artist, and year.
Despite the somewhat weak tag support, TAudioConverter is easily my favorite tool for audio conversion. Its support for 32-bit files alone should have you taking a look.