So a positive reaction beyond just having enjoyed the game, I take it?

My friends seized on Fluxx immediately and passionately; they'll often patiently indulge me in an evening but that's the one that really clicked- enthusiastic Scrabble players too. (They also enjoyed Modern Art, Princes of Florence and Cosmic Encounter but to a lesser degree than you're describing here.)  Another friend took such a liking to my copy of Set that I was eventually forced to get my own second copy; Tangoes was a big hit with her as well. And Family Business has never failed me across two decades and many different groups. (I've never seen an adult group finish a game still using their own voices.)  The Kosmos two-player line has a pretty high success ratio as well and can be a good jumping off point for new explorers. Still, often people adore what I expect to be a hard sell yet have a lukewarm reaction to my expected sure things.

I'm an easier sell, of course; I just had this experience from the other side last night with a nifty new assembly of some very old ideas called Strut!- a bit of a pile-up collision between card games like Rummy with dicefests like Yacht and Liar's Dice with a couple of Uno-esque zap cards thrown in for spice if you can imagine such a thing. A friend of the designer had noticed me eyeing the distinctive cover art- a simple but elegant rooster- and by the end of demonstrating it had convinced me to buy his own copy. Not "serious" enough for some perhaps but I have a hunch my Fluxx fans are gonna eat it up with a spoon.