I've got all the Lyrical Distortion libs. Hard to resist for $19 (they've been on sale in the past for, IIRC, $10). Some of them are flawed (fret buzzes, out-of-tune notes and stuck notes) but they're cheap and they sound pretty good. Ripper Amped is the one I've found the most use for (miked from a Mesa Boogie, so no amp sim required - just one tone but it's a good one).
As long as we're on the subject of cheap Kontakt libraries we might as well mention Sampletekk here, just in case there's anyone who doesn't know about them already. They specialize in pianos and have regular half-price sales. Most of my pianos are from Sampletekk and none cost more than $25.
Another favorite source of inexpensive libraries is
Indiginous. There are several useable libs there for $5. Check out the new Solid State Symphony for 40 bucks. And for those looking for more electric guitar sources, Torch is a cheap ($40) alternative to fancier libraries such as OTS EEG.