Sorry, I did not explain myself correctly, I was not requesting anecdotes (although I love those), I was thinking more on "were there boards that surprise you because of its power or fun or whatever?". Do you even keep some boards to study later like we do here?
Well playtest games played online all had that uh block of text from isotropic showing how they went posted in a thread so I could review them, sometimes with a sentence of description. Mostly I wasn't looking at those cards later - an exception would be like when Crossroads / Margrave was too strong and we had to work out what cards exactly were the problem. If nothing was a problem then we just moved on to the next game of random cards. When it came time to make recommended sets I made lists and then we tried them; obv. any particular combo I remembered enjoying might make it, but I wasn't saving up sets of 10.
As far as sets where we focused on them due to problems, the big one is again Crossroads at +2 actions every time / Margrave / Spice Merchant / Highway / "discard x coppers, gain a card costing up to $3+X." As I have related it turned out that Crossroads and Margrave were the issue and Crossroads was more fixable given what I was getting from both cards. Generally a power problem is more obviously confined to one card and so there's not a memorable set of 10, just, that card seems broken and we play it some more.
If it were rare for a random set of 10 to be fun, I would be desperately trying to fix that. Some are more fun than others but not by a sad margin. There are broad issues like "are there enough villages" and I look at those.
Okay I searched for "fun" in the latest version of the thread. Most of the hits are for Sir Destry saying how fun some specific card is. Most of the sets you couldn't play anyway. Here's an example set though, described as "really, really fun:"
cards in supply: Armory, Counting House, Develop, Great Hall, Hermit, Mandarin, Rebuild, Talisman, Walled Village, and Wandering Minstrel
Armory is Storeroom; Walled Village is Fortress; and Rebuild is some kind of Remodel outtake, I don't know which one. Probably one of the $5's since then you could Develop a Fortress into it. Destry specifically cited getting to go village, Counting House, Madman, and also using Hermits to draw Fortresses.