The Villa captain has been linked with a transfer to Old Trafford this season.
And having scored at the stadium just weeks ago, Grealish told Sky Sports: "That was my favourite goal ever. Scoring at Old Trafford… I've always wanted to play at Old Trafford.
"I've played there before in a reserve cup final but it's not the same when it's like that. That's obviously my favourite ground in the Premier League.
"It was one of them, as soon as I shot I knew it was going into the top corner and I couldn't have hit it any better."
He also stated: "If you actually watch the goal, I get so much curve on the ball I don't actually know I got that much curve on it.
"When I first got the ball I faced [Andreas] Pereira up and I know for a fact… I would back myself one-vs-one against anyone in the league.
"And as soon as I cut inside and I shot I knew where I wanted to put it and luckily it went in."