This could take forever...
Nearly any moment in SW could be considered one, primarily due to the way the film was cut. There's an undeniable energy to even the slightest of gestures that makes the thing feel so incredibly alive. This is what really makes ESB and ROTJ seem different.
The big ones of course: Escape pod, Binary sunset, Mos Eisley escape, Chasm swing, Trench run, Throne room ceremony, X-wing rising from the swamp, Bespin duel, the sail barge, speeder bike chase, throne room duel and many more I'm leaving out.
There are many other smaller moments that just stick with me, but to make things interesting here are a few moments that have become favorites to me due to watching and joking with friends over the years:
The most angsty pre-pubescent line in the history of time: (in a super high pitched fast paced voice) "BUTIWASGOINGINTOTOSCHESTATIONTOPICKUPSOMEPOWERCONVERTERS!"
Ben's "beard stroke" and tug after Leia's hologram.
"Freeze you rebel scum" in ROTJ when an old friend thought the line delivery sounded a bit...well they described it as sounding like an odd dirty remark where the Imperial kinda was more than interested in the Rebel...scum...
Greedo's comebacks.
But nothing compares to Dr. Evzan, Luke, Ben and Wuher's dialog in the cantina. When I first joined the site and found the GOUT I got a bit SW-mad again. So for some odd reason at any given moment where it could or could not be interjected, I would fully recite the entire "He doesn't like you" sequence and over the years this has become more and more developed until I created a new version with such additions as: "I can't have a drink-I got liver problems!" "I just cleaned up the bar!" "Come let's get trashed."
In college my roommates and I once dubbed Star Wars and ESB. Best experience ever. Completely incorrect in spots and absolutely hysterical. Examples: Beru became a heavy chain smoker, the droids became sex robots, Ben became a really crazy old man, Luke was super whiny and inconsiderate with "teen angst!...well technically more like 20-year old angst", dialogue overlapped, references made to the stupidity of the SE, in-jokes, all sound effects done vocally, Leia was puny, Han said "badass" every other line, and things like the ESB probe were dubbed with: "Jor-El placed his infant son in a small rocket ship hurtling in the direction of the Earth just as Krypton exploded."