Oscars, most definitely. I bought mine as a neophyte, not realizing that cute, extremely friendly little 1" fish with huge eyes at Petco would become a FOOT long inside of a year! He's now larger than my chihuahua!
Oscars I find to be bizarrely intelligent for a fish. They watch you and clearly vie for your attention.
Mine gets so excited as I approach the tank, he tries to jump to me and uses his tail to splash water at me if I don't give him attention (the tank is well covered yet he manages to throw some water over the top nonetheless). I often can hear him banging into the lid when he sees me in the room, trying to reach me. He's a huge, black tiger Oscar with bright orange patterns and long, flowing fins. Yet, if you ignore him completely while nearby, he'll turn grey and sink to the bottom and sulk until you play with him. (The first time I witnessed this obvious emotional and intellectual expression, far greater than I thought a fish capable of, I thought he was sick). Tapping on the glass near him, he gets all animated and his color instantly returns and splashes water at you with his tail and follows you around the room as best he can again. He's been this way since he was 3" long.
He will play with ping pong balls floating on top. Chasing them like a puppy. And clearly enjoys to be fed by hand. He also takes issue with where I place plants or ornaments and I often find them relocated the following day. One weird incident that repeated itself until I finally gave in, He had uprooted a planted anubias 3X and he not only removes it, but places it in an exact spot on the opposite side of the tank. I finally relented and planted it where "he wants it" and it's been fine ever since. I suppose I'd do the same if someone kept moving my furniture!
Perhaps his most startling display of cognition is he seems to know when it's time to eat vs time to play. If it's near feeding time, he is not playful but does the most remarkable thing. He splashes at me and when I approach, instead of playfully and excitedly approaching, he aligns himself vertically, nose pointing directly UP, almost still. Basically saying; "Hey, where's breakfast!"
Some cichlids seem to have more personality and intelligence than others. A big Oscar is a very impressive looking fish but a few minutes with them and you realize they are so interactive, so intelligent and so very personable, they become "pets".
And as someone else here said, they DO recognize individuals and sow definite preferences towards some people vs other viewers.
As a display fish, Oscars NEVER hide unless threatened. Others may suggest something different but if you're seeking a huge fish that never hides and is weirdly friendly towards people (not so towards other fish though!), I can think of none more apt than an Oscar. Mine stays out and active all day.
Oscars swim everywhere but largely occupy the center of the tank whereas arowanas are top dwellers.
Arowanas are striking but you must plan on a huge tank as they can grow to 2' or so. And their aggression can be problematic.
A huge pleco is endearing but not much of a showman!
Discus are slow and dumb and unbelievably gorgeous. But IMO, you must have at least 4 discus or they'll be too shy.
A big Pacu or Uaru also make great, giant display fishes but they won't have the intelligence nor personality of an Oscar. A Pacu is a huge, docile fish that is not that ornate but impresses with sheer size.
My last endorsement for the Oscar would be that they don't seem to mind being alone at all. Many fish are shy or even hide when alone in a tank-basically an open water danger instinct. An Oscar will ALWAYS be out. I've only seen mine hide when he was smaller than the tankmates. But Oscars grow FAST and he outgrew them in less than 2 months.
I imagine my experiences with these fishes are not without exception. But I suspect you're likely to get "Oscar" as the most common suggestion for your needs.