Did you know that Wiktionary has a dictionary of Nadsat slang? You can click on the link to check it out, but here are a few of my favourites:
Appy polly loggy, apology. A highly exaggerated way of pronouncing 'apology.'
Bezoomny, crazy. Origins in Russian. I think this sounds like a word for crazy should.
Cancers, cigarettes. Obvious,right?
Eggiweg, egg. Juvenile mutation of 'egg.'
Horrorshow, good, excellent. This just fits the novel so well. It's not just made up by sticking horror+show together, but taken from Russian хорошо, xorošó, "well", "good."
Oddy knocky, on one's ownодинокий odinókij, lit. "lonesome"
Pretty cool, right? What's your favourite?