It’s debatable. Or deliberately ambiguous, I guess. The woman (Rachel, I think?) is definitely a replicant, but I don’t know if you’d call her a sidekick.
Doc Magnus and the Metal Men
Johnny Socko
Frankenstein Jr, and Buzz
Robocop was a cyborg so technically his body was his own robot sidekick.
Anyone remember Irona the robot maid from the Ritchie Rich cartoon?
GIR, from Invader Zim.
Bruce Dern had little robot sidekicks in Silent Running, which were the forerunners of R2D2.
Also, there was a short-lived cop show in the 70’s (a comedy) in which one of the two central characters was a robot. Can’t remember the name of the show.
Mac and CHEEZE???
Don’t forget Mac and C.H.E.E.S.E. from Friends!
IMO, only Bumblebee and Spike Witwicky would count; they certainly hung out together often enough.
I certainly can’t picture Grimlock having any sort of human sidekick. 
I opened this thread specifically to make sure that Daneel was mentioned. I should have known I could count on ya, Askia.
And since I just remembered Shatner’s monstrosity called Tek, I’m going to have to remind you’uns of it, too :D. Blessedly, though, I don’t remember the characters’ names from it.
You’re thinking of Holmes and Yo-Yo Spoke, which was mentioned earlier. I know John Schuck played Yo-yo, but I don’t remember the actor who played Holmes.
Someone mentioned the Superman robots, but weren’t they retconed out?
Psst. Robby is from Forbidden Planet.
B-9 is Lost In Space.
Twiki and Doc from Buck Rogers (TV)… the dog from Battlestar Galactica…
The Superman Robots sort of existed again briefly.
That abomination was calledMuffet, a robot-copy of a species of pet they called a ‘Dagget’ help me sear the memory from my brain!
WHY DO I REMEMBER THIS CRAP!?!
MY LIVING DOLL. CBS television 1964. Julie Newmar played Rhoda an experimental Air Force Report. She is left in the care of air force psychiatrist. Robert McDonald played by Robert Cummings who must keep secret the fact Rhoda is a robot. One season.
The robot head from Lexx that existed in a constant state of hysterical infatuation for various members of the crew. Definitely a sidekick worth kicking to the side.
Surely ya’ll haven’t forgotten “Frankenstein Jr.” who had the kid as a sidekick, or was the kid’s sidekick.
And then there was that movie version of the TV series … what was it called … My Giant Robot or something …
What about the creepiest sitcom ever, Small Wonder, in which a robot scientist builds himself not a sidekick, but a nine-year-old daughter!!
The movie “Runaway” was filled with relatively crude robots doing all sorts of servant-type jobs: housekeeper, assassination weapon, picker-of-bugs-off-of-plants, etc.
The androids Ruk, Andrea, and Brown in the Trek TOS episode “What Are Little Girls Made Of?”
Thousands of androids on Mudd’s Planet in Trek TOS episode “I, Mudd”. Until they ceased being sidekicks and took over, of course.
The Humanoids in Jack Williamson’s “With Folded Hands”. although it’s debatable whether they count as servants or just solicitous overlords.
Are you thinking of Johnny Socko and his Flying Robot Evil?
He always refered to it as Giant Robot.
And IIRC, that was intended as a live-action version of the anime Gigantor (already mentioned, I know).
More recently, didn’t Giant Robo come out in Japan?
(If we’re including anime and manga here, we’ll never get done!)
How about the Stepford wives? Not exactly sidekicks, but definitely companions.
In the same vein, there’s the title character of Cherry 2000.