A LIGHTWEIGHT POWERHOUSE
MuLab is an amazing digital audio workstation with a lightweight footprint and a unique modular environment for deep editing and sound design opportunities. The price is fare too. You give it a try for FREE with a limited set of features, but with a bit of creativity you can still create some really great sounding music. For 59 EUR (about 73 USD) you can unlock the full feature set with unlimited tracks, use of as many VST plugins as your CPU can handle and more exporting options.
MIDI IS KING
I love the midi recording and editing in MuLab. It is simple, straight forward, and intuitive. While there are many ways to manipulate audio tracks and edit waveforms, MIDI is where I think MuLab really shines.