Soviet Heavy said:
Just compare the space battle from Revenge of the Sith...
to the one from Return of the Jedi
And tell me which one has you more invested.
Depends on what you mean by "invested".
The Revenge of the Sith space battle is definitely a lot more visually interesting, but the space battle from Return of the Jedi is more interesting overall because the story, characters, and directing aren't a load cardboard tripe in a rusty dumpster.
Personally, I like the move toward more CGI in movies, since it opens up a whole realm of creative expression that would be otherwise impossible. However, I agree that it's a difficult challenge to make CGI that looks "real", and creating an all-CG movie (like the Star Wars prequel trilogy and Avatar) just winds up looking exactly like an all-CG movie. Hollywood's computer animators have gotten quite good at what they do, but not good enough that they can make a movie entirely in a computer hand have it look realistic.
Personally, I'd rather see a lot more CG-animated movies where the characters don't look like cartoons (think FFVII Advent Children as opposed to, say, UP). That way you can do the whole thing in CG anyway and don't have to worry about it looking "fake".
And if you want a movie that uses a crap-ton of CGI and yet is still very compelling, try the Lord of the Rings movies. Granted, those films did use a lot of physical actors and were shot in real locations, but the judicious use of CGI really helped bring those movies to life.