What tools do you use that you couldn't possibly live without?

So for someone who lost their Sylenth1 crack I've been feeling a little deprived, found alternatives (TAL_Noisemaker is pretty good, and its free!) but it got me thinking...If I didn't have 'X' how would I cope? Then it got me thinking about how screwed I would be as a producer if I didn't have Ableton. So what do you guys rely on? Maybe its your trusty guitar or sampler, maybe its that amazing preset or sample you end up using on every single track.

I'm curious, Admit it we all have something we cant live without