Alien Romulus without question. Even if 3 episodes remain of Earth it's highly unlikely it'll change for the better and redeem itself.
While Romulus went a "little" hard on the fan service aspect, it is indeed an authentic "best of Alien" rollercoaster experience whereas Earth seems to have an identity issue (in part because too many people involved perhaps=to many chefs spoiling the broth) and is all over the place.
The xenomorphs were mostly and properly terrifying in Romulus (except the Scorched one who literally and saved Rain from plunging to her death in the elevator shaft) while it just seems confused in Earth and doesn't really seem to know its purpose.
Sets are impressive in both Romulus and Earth, although it worked better in Romulus as a whole while Earth's sets act like a theatre for actors with various talent in a badly scripted stage play directed by a highschool teacher who wanted to be a director.
Visual effects are impressive in both the film and the series.
The soundtrack is absolutely phenomenal in Romulus and its strongest aspect imo, while it's absolutely horrendous in Earth (they really dropped the ball)
I agree on Andy as well, my favorite android in the series. Likable, caring, badass and cracking terrible dad jokes. I mean how can you not like that guy. Kirsch for me is just Timothy Olyphant being himself more or less.