I used Guitar Rig 5 for a decade and disliked it. I also tried the latest version and it sounds "the same". It's not even the sound I dislike, because all of these amp sims sound the same. They all sound good, it all just boils down to the amount of different amps, cabs and effects you get.

If I were in the market now, I'd get TH-U by Overloud. I hated Amplitube 5, because its MIDI implementation is unorthodox if you use it in a DAW. I've been burned by BIAS FX2 and Positive Grid (they stopped updating it), so I would recommend BIAS X.
Neural Amp Modeler is great if you don't mind living with specific captures of tones. It's recommended to get some of the "high quality IR" packs.
I wouldn't buy the Neural DSP stuff, because it's not worth its price. It's very limited in terms of "gear" you get, while sounding the same as any other amp sim.

>tl;dr: download the demo of every amp sim out there and pick the one which offers you the most features you need. they all sound the same

bump