I spent many hours playing the King's Quest series. King's Quest 4 and 6 were my favorites. Both had great looking locations and they weren't overly difficult to solve. Kings Quest 5 looked great as well, but I felt the voice acting was a little sub par. They learned their lesson from this in 6. King's Quest 6 had some really unique locations that really made you want to keep playing to see it all. One thing about these games is they are great for all ages, both young and old could enjoy them.
The interface for 5 and 6 is very easy, it basically has all the senses, just choose one, point and click. Personally, there's something to be said for having to figure out what to type in, but I'm old school that way. ;)
Say what you will about the King's Quest series, compare it to other similar games, but King's Quest started it all. Without King's Quest, all the other games like it, may never have been.
This is well worth the price. I bought these NEW and they were worth it then. When you look at all the 3D shooters out there, arcade style games etc. This is a refreshing difference. You can relax and play this at your own pace.