City won the Premier League title in dramatic circumstances earlier this month to seal the club's first championship in 44 years.
It has capped a remarkable season for the 31-year-old midfielder, who played a pivotal role for the club - appearing in 33 league games.
"It's definitely been my best season ever," he told The Sun on Sunday. "The amount of games I've managed to get, considering the squad we've got, has been brilliant.
"I've been happy with my level of performance and I'm delighted with the way it's gone.
"Getting in Teams of the Year and winning individual awards has never bothered me.
"What is important is that fans and team-mates have spoken highly of me. And the manager too - and he's the one that really matters - so that's encouraging.
"This is the perfect club for me. The formation the manager likes to play, with me as one of two holding midfielders, suits me - even though I only scored one goal this season.
"I feel I can play on until my mid-30s. Hopefully, that will be at City.
"I don't expect to play every week but we'll be challenging for honours over the next few years and I can't ask for more than that at this stage."
Barry could not have expected his move would work out so well when he left Villa to join the club in the summer of 2009.
At the time, the switch was condemned by Villa fans and dismissed by pundits as a transfer motivated purely by money.
But Barry's decision to ignore the advances of Liverpool, who were competing in the Champions League at the time, in favour of a City side that had just finished 10th has paid off.
And the England international can now look forward to returning to Villa Park for the Community Shield showpiece against Chelsea on August 11 as a vindicated man.
Barry said: "It'll be nice going back there as a title winner, that's for sure.
"Sitting here now, I made the right decision. A lot of things were said when I left Villa, I took some stick and people questioned my motives.
"I turned down the chance to move to Liverpool, which was a fantastic club with an amazing history.
"But the decision I made was the perfect one - hopefully even the Villa fans can accept that now.
"I still keep a close eye on Villa and I'm sure they'll come good again.
"Coach Kevin MacDonald was a big influence on my career and I'd love to see him get the manager's job.
"Yes, I got a fantastic contract from City but there were others on offer. It was never about the money.
"What appealed to me about City was the chance to be part of something that would be talked about for years to come. I've never regretted it - not for one minute."
Barry added: "It's so long since City were successful so this group of players is making history and it feels great to be involved.
"We won City's first trophy in 35 years with the FA Cup and we've won the first title in 44 years. That is more important than anything."
With two years still left on his contract, Barry believes he is at the perfect club going into the twilight of his career.
He said: "You hope it'll work out when you take a big decision - it couldn't have gone any better really.
"The quality of player is so high that I can't expect to be there forever but I've had an amazing three years.
"The next aim is to be the dominant force in the next few years and I feel I can play a part in that. Hopefully, we've got that winning mentality here now."
