I refuse to watch 3 or 4 on principle. Unless one figures that the Nostromo's escape pods were subtly sabotaged, which I suppose is plausible, it's awfully convenient for Ripley to awake to a whole new hell for one sequel. To have it happen again just feels cheap.
I thought they did a decent job making it plausible in Alien3. And the idea of her being forever "haunted" by these demonic creatures, and finally driven to sacrifice herself at the end, made some kind of twisted sense.
But bringing her back AGAIN, through cloning of all things, was definitely when it started to feel cheap and gimmicky.