Friends has several storylines that stem from the characters' evolving relationships with one another. The "we were on a break" turned into a running gag (Ross, for what it is worth, not an excuse) throughout the show's run. The other major romantic conflict revolves around Monica and her two main love interests -- Richard and Chandler.
Both men have their qualities that make them a good life partner for Monica. One could see them locking horns (and they sort of did) to marry her. We are here to give you the 5 Reasons Monica Should Have Been With Richard (and 5 Why Chandler Was The Right Choice).
10 Richard: Suave
Richard may be approaching middle age when we first meet him, but man is he ever a smooth one. It is hard to imagine Tom Selleck being anything but cool after his star-making turn as the slick detective on Magnum PI.
It is safe to say none of the other men in Monica's life possess that quality. Her brother, Ross, is a mess. Joey is a clown. Chandler uses one-liners as a defense mechanism to cope with his difficult childhood. In fact, Chandler and Joey both want to be Richard, want to emulate his charm (and the way he slides a dollar bill into someone else's hand as part of a handshake).
9 Chandler: Close Friendship
What Chandler lacks in charm and sophisticated social graces, he more than makes up for through his deep friendship with Monica. Before they start dating a few seasons into the series, the two have known each other for many, many years -- dating all the way back to his college years, when he was Ross's roommate. The two know each other inside and out and have been there for each other through the good times and the bad.
Because of this, when the two begin dating and eventually marry, Chandler has her best interest at heart, not wanting to do anything to jeopardize their relationship.
8 Richard: Gentleman
Being a gentleman may fall under the first category. However, it is being defined here not by smoothness, but by niceness and honesty. Perhaps his years have taught him not to mince words and to take care of the people in his life. He makes Monica feel cherished and wanted, and somehow not like a child despite the age gap between them. There is no condescension in his relationship with her, making him the kind of man women want to be with.
Had Monica chosen Richard, there is no reason to see why he would change.
7 Chandler: Age (and other facts)
While age should not be too big of an issue if the two people are good for each other, Chandler is the right choice because he is Monica's peer and because he does not have the other elements that mark her relationship with Richard.
For example, he is not the family friend of her parents, nor was he her family's eye doctor dating back to when she was a girl. Richard has known her and her family since she was a child. That is downright weird. Chandler wins by default here.
6 Richard: Experienced
If Chandler gets merit by default, so should Richard. He may be older, but with age comes experience. Richard knows himself in ways that Chandler simply does not and has the maturity to accept what he is and is not, while his competitor for Monica's affections often hides his emotional struggles underneath miles of sarcasm and biting comments.
Chandler, for much of the series, would have to be considered immature. We also see this in his friendship with Joey, the most immature member of the friend group. Also, for bonus points, experience as a lover generally translates well in the more intimate parts of the relationship.
5 Chandler: Humble
The former Tom Magnum, for all his smoothness, cannot hide his confidence in himself. He cannot help it. Tom Selleck was something of a rock star for TV audiences in the 90s.
Chandler does not have this confidence. He has no pretensions of his own greatness. He seems satisfied to cast judgement on Joey, Rachel, or Ross for the stupid situations they get into. When Chandler begins his romantic relationship with Monica, he is more scared than anything, as the two do not want the others to find out (though they eventually do).
4 Richard: Wealthy
Monica might be one of the luckiest women in New York City in terms of her living conditions. Her apartment is subject to rent control, allowing her to pay a fraction of what it would be worth in the housing market. She is, however, subject to the struggles of most 20-somethings in the big city, with the stops and starts in her career as a chef.
Richard went through that already. He is a successful eye doctor and has no trouble paying for things. From a strictly financial perspective, Monica would be hard-pressed to find a better candidate.
3 Chandler: Sense of Humor
If Chandler has anything, it is a sense of humor. It goes from a neurotic need to avoid showing a more vulnerable side to poking fun at the others to absolute self-deprecation. He seems to have a one-liner for every situation.
Doubtless, such a habit may wear thin on the people around him, especially if you're Monica and have committed to spending eternity together. Nonetheless, Chandler knows how to laugh at himself and others. That is a positive more often than not.
2 Richard: A Good Sport
The generational divide between Richard and Monica does little to affect their enjoyment of each other. This down to a trait already mentioned -- his lack of condescension -- and his ability to adjust to the things Monica wants to do. He goes along with her. He also, on occasion, hangs out with the guys and is capable of being one of them (despite Ross's completely understandable apprehension).
Richard may be set in some of his ways, like all people eventually are, but he does not avoid Monica's friends because they are young, nor does he attempt to lecture them constantly about their attitudes. He is almost too good of a sport, as he (after attempting to win Monica back) tells Chandler to go get her and never let her go.
1 Chandler: The Right Guy
Some things just go together: peanut butter and jelly, pumpkin pie and whipped cream, sausage and sauerkraut, and Chandler and Monica. The couple's relationship goes beyond the highs of being best friends, companions, their ability to laugh at each other, their lack of ego, and all-around commitment to each other.
They stick together through the lows as well. Monica wants children, but it turns out Chandler is incapable of having children. She stays with him, and their relationship remains strong and steady to the show's end (and presumably beyond). It's not always about tangible traits.