I have used the Ripper Amped lib from Lyrical Distortion several times. It has some annoying quirks such as never-ending stuck notes when playback is stopped, and it's limited to the one sound. BUT, it's a great sound. You get a nicely-distorted Mesa Boogie tone with very little effort, and at $19 it's quite a bargain.
Since the OP mentioned Theodore Kruger specifically, if you hunt around on the net there is a Yamaha Pacifica guitar library out there by TK. If you can find it, you can download it for free. For a freebie, it was pretty impressive. Sorry, I did not make note of exactly where I found it, so you'll have to consult google.
Other serious bargains are Indiginus' $5 specials, which are all usable libraries. I have all of them except the metal guitar. Lead Guitar One and Nashville Electric Guitar are not bad, the latter being the more usable of the two. Either is a bargain for five bucks. But if you've got $50 to spend, Torch is quite nice, especially for semi-clean tones.
But of course the king of guitar libs is OTS' EEG. There are others in its league, such as the Pettinhouse products and Electri6ity. But EEG offers, IMO, the best bang for the buck. And it's on sale at the moment.