I'd like Aliens more if it wasn't pretty much a plagiarism of the 50s B-movie "Them!" only with the best parts of the first movie grafted onto it.
OK, now that's about the most ridiculous thing I've read in a while.
As for my own opinion on the films; objectively I know
Alien is, cinematically the best made film, but that doesn't stop me from liking
Aliens better. I admit I also have a real soft spot for
Alien 3, even though I hate what the writers did to Newt and Hicks, it's still a very watchable film. I mean come on, this is still a Fincher film, no matter how he'd been hobbled by the suits the direction and cinematography is still first class.
We should really consider ourselves lucky that that god awful "wooden planet" version of the script wasn't filmed instead.
And no, I didn't have much trouble distinguishing between Charles S. Dutton, Charles Dance, Paul McGann, Brian Glover and Pete Postlethwaite. Uncanny really because they're SOOO much alike.
As for
Alien Resurrection...well it's an OK film in it's own right but well below par for the series as a whole but it's not without it's charm. On the plus side it had Brad Dourif and Ron Perlman; any film with either of these two usually goes up a few notches just by their being there, so both of them is a huge help. Also, Winona Ryder get a hole blown in her gut and dropped three stories into a monster infected pit of death...yeah, I'd been waiting ages for someone to do that.

Of course in retrospect, the big plus is the crew of the Betty being the prototype for Firefly, hell some of the characters are practically unchanged. Johner and Christie are very much Jayne and Zoe.