I've been building and upgrading my system for the past 5 years and have found something I can live for for a while. if I do any more upgrades it would a pair of Wilson Audio Sophias and possibly a better speaker cable.
For the longest time I used a CJ Premier 16, Cary 805C, Transparent Audio Reference and Wilson Watt Puppy 7s. I truly loved the sound of that combination. After the second time the Cary's went up in smoke I switched to an Audio Research based system.