I still use "nifty" quite frequently.
Also "swell" and "hunky-dory", but usually when I'm being sarcastic.
Don't forget "copacetic" and "copa".
I've heard the Aussies used to say "rippa" ("ripper"), but these days that reminds me of a bad morning TV talk show.
This guy uses "dandy" to describe just about everything:
www.gunblast.com