Ripley was an interesting character in A3.
Very independent and strong without being overly boisterous. She asserted herself calmly and confidently, as per the Ripley we already knew. Her grief and shock over losing the only two people she could call friends can account for some of the thing she did, but for all that, she was remarkably well-composed.
In fact, I think A3 has the best characterisation.
As for A2, it was probably the strongest film as a piece of entertainment, but it lacks the depth that make A1 and A3 interesting to watch time after time. There was a lot of cool stuff, but once you've seen that cool stuff, it's done, stick a fork in it.
A2 was really damaging, too, due to the imitators when it came to comics. What was a potentious comic series turned out to be boring, dull and derivative. A2 itself was quality, of course, but its popularity caused it to become the standard for the franchise, rather than the much more interesting A1. A1 is waiting three hours for a prawn curry at a top-notch restaurant. A2 is getting McDonald's at midnight having eaten nothing since you got up at 8am. I sure as f**k enjoyed that McDonald's, make no mistake, but the prawn curry was to die for (and lingered longer).