I’ve been trying to think of all the words I’ve ever heard that express something that people like.
“cool”
“groovy”
“keen”
“neat”
Others?
I started wondering how many words or phrases there are or have been.
Anybody have any idea what they might have used in the 17th century?
Tidy
“bitchin’”
Sound.
Grand.
The Dogs Balls..(polite version)
Slan,
D.
Nifty
Gee whiz
Peachy keen
Hunky Dory
Wowzers
Gosh golly
Gr-r-r-r-eat (Tony the Tiger)
Splendid
Brilliant
Outstanding
Awesome, dude (Bill & Ted)
Fly (totally)
I like nice things (Tammy Faye) 
djm
Sometimes it’s cool to be hot. Sometimes it’s hot to be cool. But it’s never hot to be uncool. And it’s never cool to be not too hot. 
Canny (N.E. England - different meaning from canny in Scotland)
Mukade
Bad
Phat
Def
Tubular
Boffo
Golden (I especially despise that one for some reason)
Supercalifragilisticexpialidocious
Damn! I was just thinking of that one. 
djm
Spiffy!
sweet
rad
rad
gnarly (dude)
boss
Like- OHMYGAWD!
jsluder - get OUT of my head!
funkadelic
ain’t it a peach
fantabulous
screamin’
happy as a gopher in soft dirt… (I know this doesn’t really qualify, but it remains one of my favorite sayings)
zonkers
super
mega
cosmic
Okay, but we should warn people first…
This type of thing could probably constiute its own thread. Like: Happy as a turkey on Boxing day.
djm
Skookum! (I think this is pretty regional to Western Canada).
I don’t know if these terms are used any more but far out, outta sight and something else used to be used be used by jazz musicians, hangers on and fans.