Good thing, that you added the "in my opinion" line there. Obviously my favorite version is always the newest version.
As I'm one of those, who always wait to get new stuff to play with, and can't really go to play older versions without getting bored and annoyed by lacking content. For me it's not fun at all. Beta terrain generation aren't that "WOW" either. It's actually quite "MEH".
Now what we have now isn't that much better, but I still prefer the modern terrain generation.