"Dooks, Waterville, Ballybunion Old, Tralee, and Lahinch are the can't miss courses. Everything else is good but not great."
That's almost correct except that missing the Cashen Course is a sin: empty, wild, immense ( world class #3,4,6,7,8,11,13,14,16,17,18) most holes will take your breath away, just skip out-of-place number 12, you'll save 10 mins. It's Tralee on steroids. And better for that.
And, as someone pointed out, 9 holes at Castlegreggory is a fun way to spend 2hrs in a beautiful remote setting.