Data

"Please continue the 'petty bickering'." - Data to the party guests

Data : "You are capable of great sadism and cruelty. Interesting. No redeeming qualities."
Armus : "So what do you think?"
Data : "I think you should be destroyed."

People :

Armus, Data

"One is my name. The other is not." - Data to Pulaski; on her mispronunciation of his name

Data : "It is a matter of perspective Doctor. In the strictest sense, I did not win."
Everyone : "Data!"
Data : "I busted him up."

People :

Data, One

Data :" Sensors show life forms aboard, but I am unable to ascertain whether they are awake or dormant. However, the vessel's propulsion systems are inactive, so I would hypothesize that the crew is asleep."
[The Tong fires disruptors at the Enterprise-D]
Data :"...however, I could be in error."

People :

Data

"This is just a thing, and things can be replaced. Lives cannot." - Data to Gosheven

"Since there is no known natural phenomenon capable of travel at warp velocities, there are but two possibilities. Either it is a sensor malfunction, another ship is following us covertly." - Data to Picard

"Is that the purpose of existence? To care for someone?" - Data to Elbrun

"I cannot permit this to continue..." - Data to Fajo

"Through joining, they have been healed. Grief has been transmuted to joy. Loneliness to belonging." - Data to Troi

"The Enterprise is not a ship of war. It is a ship of exploration." - Data to Ishara

"As I experience certain sensory input patterns, my mental pathways become accustomed to them. The input is eventually anticipated and even 'missed' when absent." - Data to Ishara; on his definition of friendship

"I would gladly risk feeling bad at times, if it also meant I could taste my dessert." - Data to Timothy; Nice foreshadowing of Generations here.

"It is interesting that people try to find meaningful patterns in things that are essentially random. I have noticed that the images they percieve sometimes suggest what they are thinking about at that particular moment. Besides, it is clearly a bunny rabbit." - Data to Guinan; on the nebula cloud formations

"I have often wondered about my own mortality as I have seen others age around me. Until now it has been theoretically possible that I would live an unlimited period of time. And although some might find this attractive, to me it only reinforces that fact that I am... artificial." - Data to Geordi

"Felis Catus, is your taxonomic nomenclature,
An endothermic quadruped, carnivorous by nature,
Your visual, olfactory, and auditory senses,
Contribute to your hunting skills and natural defenses.
I find myself intrigued by your sub-vocal oscillations,
A singular development of cat communications,
That obviates your basic hedonistic predilection,
For a rhythmic stroking of your fur to demonstrate affection.
A tail is quite essential for your acrobatic talents,
You would not be so agile if you lacked its counterbalance,
And when not being utilized to aid in locomotion,
It often serves to illustrate the state of your emotion.
Oh Spot, the complex levels of behavior you display,
Connote a fairly well developed cognitive array,
And though you are not sentient, Spot, and do not comprehend,
I none-the-less consider you a true and valued friend." - Data; "

"It is true I am acting on my personal beliefs. But I do not see how I can do otherwise." - Data to Riker

"I got angry." - Data to Riker

Riker : "Data, we need you to scan the planet for lifeforms."
Data : "I would be happy to sir... I just love scanning for lifeforms. [sings] Life forms... you tiny little life forms... you precious little life forms... where are you?"

People :

William T. Riker, Data

Queen : "Do you always talk this much?"
Data : "Not always. But often."

People :

Borg Queen, Data

Data : "The B-4 is physically identical to me, although his neural pathways are not as advanced. But even if they were, he would not be me."
Picard : "How can you be sure?"
Data : "I aspire, sir. To be better than I am. The B-4 does not. Nor does Shinzon."

People :

Jean-Luc Picard, Data

"Goodbye." - Data to everybody