I'll start off by listing mine:
The T-800, Terminator 2: "I know now why you cry, but it's something that I can never do." Gets me every damn time.
ADA, Zone of the Enders: I think I'm the only one who played this game more than the MGS2 demo that came with it. I will never not laugh at the exchange of "You may speak like a human, but you're still a heartless computer, aren't you?" "That is correct. What is the problem?"
Codsworth, Fallout 4: He survives the nuclear holocaust despite not having a bunker and waits 200 years for you to come back. When you look at what changes his relationship with you, he mostly just wants you to be nice to people. I never swapped him out as my companion.
B.O.Y.D., Ducktales 2017: He's adorable. 'nuff said.
I'm a big fan in general of Futurama robots because despite being built by people and sold as tools essentially, they've managed to start a religion complete with a real Hell and seem to operate with a degree of autonomy that makes you wonder who built them and why. Like, someone decided we needed a Hedonism Bot and constructed one.
I have a real soft spot for robots that look like something out of an old timey sci fi with tank tracks and gadgets that do really specific things.
Any cardboard box covered in foil robot is the best robot