Best amp simulation plugins

UAD unison plugins went on sale today and I wanted to get some of their amps. I’ve run the demo on a few and never really been able to get a great sound with them (which I’m guessing is user error) so I’m wondering what people have had the most luck with as far a sound design and mixing.

If you have native instruments guitar rig pro has some excellent amps in there. My favorite is the gratifier. True to its name. I also like the guitar amps in logics own stock plug ins I have never tried uad so I can’t say. Good luck!