I think that's it. lol
Terminator 2 and Godfather 2 are two other very worthy sequels.
The original Blade Runner is a magical film, I dont expect this sequel to have any moments like Rachel holding up the implanted memory picture of her with her mother or Roy Battys dying monologue. The brilliant score by Vangelis is also unlikely to be equalled.
On the other hand it will be in 3D! Theyll get some of my money for sure.
GII is basically the exception that proves the rule that sequels are typically just a way to sell tickets when you're running out of original creative ideas.
I could not disagree with you more about Alien vs Aliens. Like the Matrix, the original Alien movie was a fresh take on interesting concepts- in this case, an incredible biology that was great and now much copied for sci fi fans. The sequal was just a dumb big-budget dime-a-dozen fight fest.
The first Rambo movie was the best, and was based on the book. (Both Rambo & the Sheriff died at the end of the book...so some tweaking was necessary to get sequels.) The last movie was good because Rambo returned home, bringing some closure to his chaotic life. The in-between movies were dreck. (But, I watched them anyway.)
The 2nd Godfather is believed by some to be the equal or even superior to its predecessor.