Which SF movie or TV show portrayed Aliens either really well or really poorly. Do you like your aliens basically humanoid wearing silly masks or do you like/hate the totally different concept like Yaphit in the Orville? Where does the Star Wars bar scene rank.
While I totally understand why most TV-and-movie(-intelligent)-aliens prior to the 2000s followed the 'man-in-rubber-mask' body-plan, I think with the advent of seamless CGI, there's a lot less excuse for that nowadays than there used to be.
So e.g. Mos Eisley Cantina just about gets a pass, but anything done in the last 10-15 years, not so much. Counterpoint though: technically the Xenomorphs in the
Alien movies were men-in-masks as well, but the suits (and the gaits) were sufficiently, erm...
alien, that it wasn't immediately obvious.
Sooo... hmmm, tricky...
Apart from the Na'avi (i.e. mocapped men-and-women-in-masks!),
Avatar showed some great alien species -- just not intelligent ones. And whatever you might say about the acting quality (or lack thereof),
Valerian had some funky aliens (not the main characters, obvs).
(Off the top of anyone's head, have we actually seen [m]any [new] 'alien'-species
characters in the Sequel Trilogy yet? i.e. not including the blue-milk space-whales and the space-horsies? The OT -- at least ANH and RotJ -- had a Wookie, Ewoks, Mon Calamari, a Sullustun, Twi'leks, most of Jabba's court...)
I would
love to see some more varied intelligent-alien-species body-plans than the 'roughly humanoid' that movie- and TV-audiences generally get presented with, though - because there is so much good sci-fi out there that's
never been adapted. For example, Larry Niven invented quite a few non-humanoid intelligent aliens in his various books (e.g. Puppeteers, Outsiders, the Fithp). David Brin's
Uplift-universe has some good ones too (not just mammalians: also insectoids, avians, reptilians), as does Julian May's
Galactic Milieu (there was at least one intelligent
vegetable species in there, IIRC), and Iain Banks'
Culture (e.g. the Affront, and the Chelgrians). And in Peter F Hamilton's
Night's Dawn trilogy, though the characters were mostly human, there were also a few intelligent-insect and -elephant type aliens; the 'Starflyer'-ecology in his
Commonwealth Saga was an interesting idea, too.