Anything I have ever paid for underwhelmed me.
Here's some freeware that will blow your mind.
The lepou or Poulin stuff is GODLY, sounds amazing. Engl, Mesa, Marshall, Soldano and other sims
Second place is the Nick Crow stuff and TSE tied. These guys focused on 6505/5150 type sims
Third place is the Ignite stuff. Ignite has a deadly bass sim and some nice guitar stuff too.
Some of these guys also make stomps that are pretty awesome as well.
All free and all beat the crap out of anything else. Mix in some effects that can be had with reaper or most DAWs if you need some delay and such and you are in business. However if you are looking to involve a lot of effects then you may wanna pick up guitar rig or revalver. If you are a fan of VST tweaking then Headcase would be the purchase for you.
For me it's the free stuff mixed with the 7 deadly sins cab sims pack which can be found via torrent or pay for the redwirez / ownhammer cab sims, cheap and they sound incredible.
If you need any more advice or help with VST stuff, PM me, I have tried it all.