Besides E.T., Short Circuit, Star Wars and 2001 as others have mentioned, I’d also recommend Hello Dolly, City Lights, Treasure Planet, I Robot, and Silent Running.
Hello Dolly is pretty obvious, since its songs and footage have been heavily featured in the film. But Stanton and Co. made a brilliant choice in choosing this film, because (mild spoilers) the movie actually parallels Wall-E in many plot themes. The impetus to go out of your comfort zone and explore the world, the sheer wonder of love at first sight, that money and wealth should not take precedence over friendship and love, and to be sweet and kind to everyone (as personified by Streissand’s adorable Dolly Levi). It is also quite possibly the happiest musical I’ve witnessed (props to the amazing Gene Kelly for the jaw-dropping choreography and the awesome Louis Armstrong for singing the cheerful title song)
City Lights is another good choice, as Stanton and Co. may have been inspired by Chaplin’s silent antics, and this movie is also a good shadow of Wall-E’s plotline. In a nutshell, Chaplin’s signature character, The Tramp meets a pretty but blind flowergirl and instantly falls in love with her. She mistakes him for a rich person and is attracted to him. Through a series of comical misadventures with a businessman he saves from suicide who only remembers him when inebriated, The Tramp endeavours to come up with the money to save his sweetheart from home eviction, and ultimately win her heart. The ending is particularly poignant and touching.
Treasure Planet bears many similarities to Wall-E’s space-opera aesthetics, and as one of the last 2-D/3-D animated hybrids from the studio (at least until Princess and the Frog) it’s worth a look at for its stunning visuals and whimsical steam-punk take on the classic Treasure Island. The dialogue is witty, the scenery captivating, and the action sequences riveting. Of interest to Wall-E fans should be the malfunctioning robot, B.E.N., whose initialized name and quirky nature should prove appealing. Even his eyes bear a slight resemblance to Wall-E’s.
I Robot bears no resemblance whatsoever to Asimov’s landmark sci-fi book (of which I’ve read, and is remarkably excellent in imbuing robots with human personalities and feelings) besides the appearance of Dr Susan Calvin and Sonny the sentient android. Nevertheless, if you can look beyond the requisite mind-numbing gunfights and car chases, there are some pretty interesting themes touched on, like the Robot Singularity and the possibility of robot rebellion (with an AUTO-like villain to boot) and of course, Asimov’s infamous Three Laws of Robotics.
Silent Running is the only one I have yet to see, but apparently it’s also an inspiration for Wall-E. A botanist on board a spaceship harbouring Earth’s last nature reserves goes renegade when he is instructed to jettison his beloved forests and return home. Accompanied only by three robots, he ponders the fate of his last pocket of nature and the murders of his fellow crew members in this far-looking speculative film. It sounds quite similar to the Captain’s fight with AUTO over the saving of Earth, and apparently the wordless robots are just as expressive as the ones in Wall-E. It was also the inspiration for Mystery Science Theatre, which I’m just as interested to see.
Whew! So yeah, that’s a fairly long post there. I’m now on a Wall-E inspired film rally now, I’ve borrowed the first three from my library, and I’ve just loaned 2001 yesterday with plans to watch it in the coming days. I’m really want to watch Silent Running, but unfortunately they only got a VHS copy! If only Wall-E could loan me his player.