An old-school interface belies Sony Sound Forge Audio Studio 10's power and versatility. It's limited to stereo, though; no 5.1 or 7.1 surround sound. See all: PC Advisor Software Downloads.
Sony's Sound Forge Audio Studio 10 may not be the most modern-looking of applications, but it's an audio editor with impeccable 2-channel chops. There's no support for 2.1, 5.1 or 7.1 multi-channel audio, nor piping to the Celemony Melodyne editor. But it supports just about every other audio editing feature, including the vast majority of VST effects plug-ins. See all Audio/Music software reviews.
SFAS imports a wide variety of stereo files including wave files up to 32-bits/192kHz, Windows and Apple lossless, FLAC, and Ogg. The only file type it wouldn't load was my APE file. Editing is extremely quick and facile, and there are numerous time-saving presets for diminuendos, dynamic swells, flanging, normalizing, etc. You may also save your own presets. The program includes Sony's Audio Enhancer, a very capable multi-purpose mastering tool.
One disappointment with SFAS was with its own noise reduction. I had success only with small amounts of background noise. It's simply not in the same league as BIAS SoundSoap 2 or Izotope RX 2. The Izotope plug-in that comes with the program is much better but it's not included in the 15-day trial, which is otherwise fully functional. The other effects and processing are top-notch.
Sound Forge Audio Studio is very capable. However, as with every pay-to-play audio editor, I have to first point you to the slightly clunky, but capable and free, Audacity. See also: Sony Acid Music Studio 9 review.