There are plenty of reasons to support City, and Aguero is certainly one of them.
From my experience, it seems there are two types of sports fans.
The first type supports their local team by default. It is the team their father followed and it is the team their brother has season tickets for, so the allegiance thus comes almost by birthright.
Then you have the other sort: the fan who comes to a sport late or who never much cared for any particular sports outfit for whatever reason.
As the Premier League continues its progress into the American consciousness, it is pretty clear that most new fans are going to be looking for a rooting interest.
Manchester City fans like myself have myriad arguments for backing the Sky Blues.
But more than anything else, friends don't let friends support Manchester United.
Bill Simmons of ESPN.com (and now of Grantland.com) famously wrote this about Manchester United as he eliminated contenders to be his favorite Premier League team:
By all accounts, they're the New York Yankees...everyone hates them, and even their own fans don't enjoy rooting for them that much. Can you imagine knowing a foreigner in their mid-30s who was looking for a baseball team and announced, "I'm going with the Yankees!" Wouldn't you hate that person? I don't want to be that guy.
This is not just "how to pick your favorite Premier League side" advice.
Don't be that guy—these are words to live by.
The sky blue uniforms are pretty terrific.
Bill Simmons' "Choosing My EPL Team" column on ESPN.com from over seven years ago has so much good material in it that I could probably base half the slides in this piece on that column.
With great restraint, though, I will make this second slide the last one I crib from Simmons.
Writing about City's colors, Simmons gushed:
Baby blue, a shade lighter than the UNC Tar Heels. Probably the sweetest jerseys in the EPL. I can't emphasize this strongly enough -- these things are SPECTACULAR.
When a man is right, he is right. City's sky blue kit is phenomenal.
This scene was special because it was so unique.
Choosing Manchester City over Manchester United is an easy decision for anyone who enjoys the thrill of the chase.
When Sir Alex Ferguson retired from United in May, the Independent ran a story titled, unironically, "The 49 Trophies of Sir Alex Ferguson."
Ferguson won the vast majority of his career hardware with United, including 13 Premier League titles, five FA Cups and two Champions League crowns.
City have won one FA Cup and one Premier League title in the past 44 seasons.
Join City and revel in the excitement of achieving something special when they win.
Join United and experience boredom when they win and spoiled anger when they don't.
Is it confusion? Is it constipation? Maybe you don't want to know.
As Manchester United manager David Moyes is finding out the hard way, being the guy who follows The Guy is no bargain.
Sir Alex Ferguson's record at Manchester United is unlikely to be matched or even seriously threatened in the future, primarily because United's days as the only big-spending Premier League side seem to be over.
Still, United partisans are always going to compare Ferguson's successors to the great man. And the successors are always going to suffer for the comparison.
Moyes' current struggles are casting a pall over United's season.
Expect more of the same for the foreseeable future as United's manager—whoever it is—struggles to lurch out of Ferguson's all-engulfing shadow.
Ferdinand is just one Red Devil whose best days are behind him.
This, unfortunately, is to a great extent still your father's Manchester United.
Ryan Giggs, 39, is still an occasional starter for United.
Patrice Evra and Michael Carrick, both 32, have combined to start 13 of United's 14 Premier League matches this season. Nemanja Vidic, 31, has started six league matches.
Perhaps the best example of the lengthening teeth of United's squad is Rio Ferdinand, 34, who has made six Premier League starts himself. Per the Mirror, Ferdinand is at least being truthful about his falling form:
Rio Ferdinand has admitted on Twitter to being below his best this season after being praised by a Manchester United fan.
Replying to a tweet which said "I love your defending man", Rio took to the social network to reply "you missed my last couple of games obviously #WillDoBetter".
Football is a young man's game. United are not a young side.
Comparatively, City's biggest stars are still relatively young and on the come.
Sergio Aguero is 25. Joe Hart is 26. David Silva is 27, as is Vincent Kompany. These are the established studs.
Future years might see huge contributions from the likes of Stevan Jovetic (24) and Jack Rodwell (22).
City have players you can get to know today and in coming seasons.
Even United fans have to admire Rooney with one eye closed.
Wayne Rooney is Manchester United's best player and still one of the premier scorers in world football.
You just would not want him in your home.
FoxSports.com helpfully put together this compendium of Rooney's shenanigans on the pitch a couple of years ago.
Unfortunately for Rooney, he has even more trouble being good away from football.
There are other problem children on the red side of Manchester. Nani, for one, is such a notorious diver that his former manager, Sir Alex Ferguson, had to go out of his way to deny Nani's diving.
Ashley Young is not exactly immune from similar charges himself.
For a side prides themselves on being the class of the Premier League, United sure seem to have a lot of footballing frauds in their midst.
"See, David, when I send Nasri in like that, it's magic I tell you."
Manchester City manager Manuel Pellegrini's commitment to aggression makes City a side that, when they are right, are a complete joy to watch.
"We will try to be an attacking team. All the teams I worked at before did that and that is why I am here now," he said, according to Goal.com.
Perhaps a better version of that quote above predates Pellegrini's time as Manchester City manager.
Per Lee Roden of talkSPORT, Pellegrini not only prefers attacking football, he outright dismisses any other way.
My teams think more about building than destroying, and I don't like those who prioritise destruction through constant man-marking and fouling. It bores me, I'd never go to see that kind of football.
If City's 4-1 shellacking of United in the season's first derby did not convince you of this, nothing will.
Moyes' tortured mien has drawn criticism.
If Manchester City manager Manuel Pellegrini is trying to create the greatest show on turf, Manchester United manager David Moyes is trying to succeed by first not failing.
That does not exactly translate to thrilling football.
As Michael Cox cogently wrote in assessing Moyes' style for The Guardian:
Whereas other managers believe paying too much attention to the opposition affects self-belief, the Scot is a naturally reactive manager who varies his side's approach to nullify the strengths, and expose the weaknesses, of a particular opponent. Sometimes this reactivity can become negativity, and while Moyes has often frustrated big sides in the Premier League he has rarely beaten them – especially away from Goodison Park.
In other words: B-O-R-I-N-G.
United these days are the worst kind of side. They are not very good, and they are not very interesting, either.
Sheikh Mansour fills the Etihad with only the finest.
One of the best reasons to choose to follow Manchester City instead of Manchester United is money.
Sheik Mansour's money, that is.
Per Ken Belson of The New York Times:
Sheik Mansour has a portfolio of political and economic responsibilities that include overseeing a major oil company and his country’s sovereign wealth fund, which is thought to be worth $650 billion.
The sheik's infusion of funds into Manchester City instantly transformed City from a perpetual underdog in Manchester to a worthy contender against Manchester United for the city's affections.
Just this summer, City spent over £100 million to acquire Fernandinho, Jesus Navas, Alvaro Negredo and Stevan Jovetic.
As long as Sheik Mansour owns Manchester City, the tide projects to run high.
United fans are rightly worried about the club's fiscal picture.
While Manchester City are awash in Sheik Mansour's oil riches, Manchester United are awash in red ink.
Per David Conn of The Guardian, "Manchester United spent £71m in 2012-13 financing the cost of the Glazer family's debt-laden takeover of the club."
And that is not nearly the worst of it:
The £71m finance costs take to £680m the total cost to United in interest, fees, bank charges and debt repayments of the Glazers' 2005 takeover of the club. The £525 million the American family borrowed to buy United was loaded on to the club to repay, and eight years on, despite so much interest paid, United's debt at 30 June was still £389 million.
The Glazers are finding out that the old adage is true. It is easy to buy a yacht.
It is hard to own one.
As a result, United's transfer dealings in recent seasons have been restricted to one plum buy per summer transfer window.
The acquisition of Robin van Persie certainly paid dividends. Whether Marouane Fellaini will do the same is still in question.
Still, a club with upper-tier aspirations risks a lot in devoting their whole transfer budget on one big signing.
Do you really want to sign on for that?