The old PodFarm gx ones sound best, imo. LePou are 2nd and solid with good IRs (I like Rosen's).
The guitar's pickups matter a lot. Humbuckers tend to sound a little better than single coils. Also, I used to have an ART Tube MP preamp, and I swear sims sounded better through that than my Focusrite interface.
Other than that, it's gain staging it properly (a lot of sims presets clip by default, and using your interfaces I/O to manipulate the sound) and EQing out the bad frequencies. A re-amp box is a better option if you can play loud for just 5 minutes per day to re-amp a track.