Judge Dredd had a robot companion called Walter the Wobot.
( the fweind of Dwedd).
SF worldbuilding at
http://www.orionsarm.com/main.html
Pneuman from the comic book series Tom Strong.
What I was thinking of was, The Iron Giant.
When you think about it any of the Love Bugs could qualify. Afterall, the VW was a machine capable of independent thought and functioning which formed a bond with its owner and functioned within a loving framework from then on.
Robin William’s version of The Absent Minded Professor had Weebo and Weebette.
Booster Gold’s little flying robot Widget (Is that its name? I may be conflating it with Excalibur’s Widget)
Here’s an obscure one:
Treasure Chest, a comic book that used to be distributed through Catholic schools in the 50s and 60s, had a couple of running serials. One of them was the Jonny Quest-inspired “Sock Jones.” Among the cast was his robot sidekick, Zork. I wonder if anybody else on the SDMB has any memory at all of this amazing comic?
Praise from Chronos! I am not worthy.
Krokodil, with ALL the comic book characters I mentioned, how in the WORLD did I forget Booster Gold’s robot Skeets?
Supreme’s Suprematons.
Detective Joe Pi, from TOP TEN
Warlock, from the New Mutants.
Fear Itself, good, good call with Small Wonder. Waaaay back a friend and I drank shots as we topped each other naming bad TV shows. I should have won, but he claimed he never heard of “Bowling For Dollars.”
Remember Automan?
I can’t believe no one’s mentioned Floyd, from Planetfall. sniff So sad. “Sing me a song while I die.” sniff
Howabout the Terminator from T2? “COOL! My own Terminator!”
Anime is also chock-full-o robot partners:
Niomi Armitage, the robot from the Armitage movies
Maj. Motoko Kusanagi from Ghost in the Shell
The robot girl from Metropolis
that’s all that comes to mind.
What, no one’s gonna mention Copelia ?
and my personal favorit… PygMalion ! 
Read your classics!
Oh, and there was a robot in Space Camp, too. While I don’t remember his name, either, I do remember that he was the one who caused the “accident”.
And I’m not sure if he counts as a robot (he’s a computer, but does have direct control over a wide variety of machinery), but how about Mycroft from The Moon is a Harsh Mistress?
While Brillo may well have been the source for Holmes and Yo-Yo, Ellison and Bova actually sued (and won) against a television program called Future Cop.
Sir Rhosis
How about Robocop?
Oh yeah…and lets not forget Steve Guttneburgs robo-sidekick Johnny Five
Um … it might be faster (like, way faster) to come up with a list of robots who weren’t partners with humans.
Considering that the whole purpose of the robots we real-life humans are designing now is that of mechanized servants.
I think once your into comics, you’re going to have a very long list. At one time robots were Big Stuff in the comics. In fact, IIRC there used to be a comic ABOUT Magnus, Robot Fighter. I’m betting he had good robots to help fight the evil ones.
And if you’re going for books, Iain Banks’ AI robots, esp. the intelligent knife missiles, are about as scary as they come – and they are companions to the humans they are with. In fact, Banks wrote a very powerful short story about a man in an AI space suit who has to, with the help of his suit, walk for days to reach an outpost on a planet he’s marooned on.
There was a robot sidekick in one segment of the first Heavy Metal movie.
(Voiced by the immortal John Candy, I might add…)
“Immortal” being a relative term, here…