Meh, I wonder how much of it is rose colored glasses. There is one KQ (forgot which one) where you have to walk through a bunch of thorny bushes to get to a castle. Any touching of the plants = instant death. This was essentially an exercise in 'take a few steps, save game, repeat'. Where was the fun in that? There were many things like that, although I forgot most of them of course. Many of the mechanics just felt like 'hard for hard sakes', not 'hard for fun sakes' - of course with the idea that harder is more fun, but still.

In that same vein, Lori and Corey Cole are working on a game right now: http://hero-u.com

Sierra was definitely a seal of quality for a time, like Blizzard, Disney or Nintendo-- anything they produced was going to be very well polished and even if it wasn't your thing, you could tell it was a solid product.

Adventure games died for a while, but there are some good ones that have come out since the 90s. The Shivah captured a lot of the humor of the genre but with a distinctly Jewish flavor, and I found The Cat Lady to be far more captivating than Gabriel Knight or Phantasmagoria.

Favorite? Mine was King's Quest IV.