im gonna go back on what i said and add that if you want to be the next deadmaus then serum is really what youre looking for. as for your question.. well.. it really depends on what youre looking for. if its just 'phat ass saws' then sylenth makes those really accessible. if its synths in general maybe something like reaktor or omnisphere even tho theyre different beasts. These are just general starting points. For example something like tassman will get you places where other synths wont. Most of the 'best' synths are synths that can do many things which is great but if you want to get the most out of software you want diversity. Instead of using absynth for synths AND bass maybe try Lush and subboombass(random example). Its also pretty hard to bash one synth over another on their own. But tracks made out of 10 instances of massive and serum will not sound as 'professional'(good) as a tracks with serious vsts(not massive or serum) picked for their specific purpose. There are ALOT of good vsts out there so naming them is beyond the point its just up to you to set standards for your method and see what works best.