Seen a mention or 2 about Kontakt in this thread. FWIW, I just saw that Komplete 10, which includes Kontakt and MUCH more, is now selling for $199 since Native Instruments just announced the upcoming release of Komplete 11. Unfortunately, I just paid $399 since I bought it 4 days before the announcement and subsequent price drop. Bummer. :(

Having just promoted Komplete, I'd also suggest not becoming a "collector" of plugins. In other words, really learn and master a few of them, then decide if you need others that do something that the ones you've mastered can't do. I know I have redundant plugins that I didn't need to acquire, as something I already had could have done the same thing had I just taken the time to really learn that plugin. Easier said than done, obviously.