I've used Audacity and Soliton but don't remember them well. OK I think. For freebies I suggest you get several. Each has it's own set of goodies. Try NoNags Audio Editors. I don't think Asia is actually available. I got a copy after a huge Net search but it was nothing special.
Among not-so-cheap-payware are GoldWave, Sound Forge (Sony) and CoolEdit Pro/Adobe Audition. I like GoldWave the best and it's also the cheapest.