Aspect

I've used Aspect for a number of years, and find it a really good soft synth with great flexibility for sound design. The different modulation and routing options are very flexible. As an example, you can have the filters running in series or parallel or have each oscillator going to its own filter. Plus it has unusual sections such as multipliers, adders and inverters. Having a third LFO is a bonus. Ideally I would like an extra oscillator or a sub oscillator, but as it is you can get a great range of sounds from it.