The relationships of Ron Stoppable.
Ron's crush in early Season 2; she might have been his first girlfriend. However, sometime prior to graduation from high school, Zita is implied to be dating Ron's best male friend, Felix Renton.
Addressed in "The New Ron", "Animal Attraction", and "Ron Millionaire". In "The New Ron", Amelia crushed on Ron because of his new hairdo. When he lost the haircut, he lost Amelia's interest. Ron got excited in "Animal Attraction" when he found out that Animology said that Amelia was his soulmate. Ron was also seen flirting with Amelia in "Ron Millionaire".
Tara is the most well-known of Ron's love interests, with the exception of Kim and Yori. Tara is one of the many girls that gazed at Ron in "The New Ron". Unlike the others, she saw Ron's true self afterwards, and she apparently liked what she saw. Another indication that Tara liked Ron was seen in "Number One", where Bonnie buys new cheerleading outfits to win the team over; Tara refers to the uniforms as "badical", a term which Ron is more known for using. She even kissed him on the cheek in "Sink or Swim" after he rescued the cheerleading squad from Gill the mutant; that was the first kiss seen on the show.
Yori, is a student of the Yamanouchi ninja school in Japan, who had a crush on Ron. After Kim, she appears to be the most popular of Ron's romantic interests. In "Exchange", Ron was shown repeatedly to be interested in Yori, both at their first meeting where he was stunned by her appearance, and again later when he informed Fukushima that he will be the one to save and win the pretty girl's affections. However, Ron was not aware of her affection for him until she was leaving at the end of their second meeting; even after Yori kissed his cheek while leaving, Ron didn't fully recognize that she "liked me liked me" until Kim explained it to him. On their third meeting, Ron told her of his newly-formed relationship with Kim, which she accepted with good grace. Kim has repeatedly displayed jealousy towards Yori, possibly due to Kim's belief that Yori is her greatest competitor for Ron's affections.
Bonnie has shown be attracted to Ron in a few episodes such as "Ron Millionaire" where when she was immediately attracted to Ron when he got his Naco Royalty check and "Homecoming Upset" where Ron is elected Homecoming King and she is elected Queen.
The eponymous star of the show and Ron's best friend; at the end of Season 3, they became boyfriend and girlfriend. Throughout the series, it was hinted quite regularly that Kim and Ron would eventually come to date each other. This was made fun of in the episode "Bad Boy", in which Kim and Ron, while watching a soap opera, say "Oh, please! Are they still teasing that Charity and Danny are gonna get together?" "Like that's ever gonna happen, it would end the series!" Little awkward moments between the two became common during their multi-gender relationship. One example of this is that Kim first gave Ron a kiss on the cheek under a mistletoe in "A Very Possible Christmas". The directors of the show, as stated in an interview, had chosen to couple Kim and Ron so as to impart the moral, "give geeks a chance." Kim and Ron had a very durable friendship before their romantic involvement in So the Drama. This is suspected by some fans to be a type of maxim communicating the idea a strong friendship should first precede a relationship. As of Season 4, Kim and Ron are dating. It was believed by some fans the addition of the element of romance would be a positive thing, although some others were opposed to it and feared it might cause the show to jump the shark (during the episode "Ill Suited" the show makes reference to this when Ron asks Kim if she had ever water skied over a shark, as in a dream he had). Schooley and McCorkle noted the potential risk, admitting that while Kim and Ron's blossoming love gave them a chance to do something new with the characters, the relationship had to be handled delicately to avoid turning the series stale. In the episode "Clean Slate", Kim acknowledged that she loved Ron. The fact that her impending death (but she didn't die) spurred him to destroy their adversaries in "Graduation", would illustrate the fact that this love is indeed mutual; the ending of the series finale heavily implies that Kim and Ron's relationship will endure.
One of his main foes and archenemy is Lord Monkey Fist. Once a respected archaeologist and expert on all things Simian, Lord Monty Fiske turned to evil and tricked Kim and Ron into helping him recover a jade monkey statue from a temple in Cambodia. He spent the family fortune on radical genetic mutation, which was revealed in the Season 2 episode "Partners" to be the work of DNAmy. He is a master of Tai Sheng Pek Kwar, also known as Monkey Kung Fu. In his debut episode, "Monkey Fist Strikes", he succeeded in his goal of obtaining the mystical monkey power and changed his name from Monty Fiske to Monkey Fist in an appropriately ironic anagram. Ever since their first encounter, Monkey Fist has considered Ron his greatest/arch-enemy, although he once told him, "You're not an arch-foe, you're an arch-bumbler!", showing that he get frustrated every time he loses to Ron. He, Ron, and Rufus are the only ones who possess the Mystical Monkey Power, although Ron's adopted sister Hana is implied to have it as well.
Ron has not actually fought Monkey Fist in a one-on-one battle since their first encounter. In many ways, Ron and Monkey Fist have a similar relationship and similar personalities to that of Shego and Kim. In the one episode where Ron and Monkey Fist fought directly, Ron displayed ability he rarely shown in any other episode. Of all of Kim and Ron's adversaries, Monkey Fist alone is able to remember Ron's name most of the time, something which Ron has admitted he respects.
As Season 4 draws to a close, Monkey Fist is reverted into a stone statue after he gives up his 'destiny,' to follow the path of The Yono, and is unable to free himself as of Ron's graduation from high school. Presumably, this is the first time a recurring enemy appeared to have been "killed off". Although others, including Kim, were turned to stone by The Yono and were not dead, so Fiske's final fate is actually open-ended.
While Drakken is clearly Kim's arch-foe, it almost always seems to be Ron that he ends up duking it out with in battle. Still, even if their fights have never been truly epic confrontations, like Señor Senior Jr., Drakken has proven to be one villain that Ron can actually manage quite handily without the use of his Mystical Monkey Power. In "A Very Possible Christmas", the two of them got into a long standing battle which resulted in Drakken being unable to go the distance with him. Also, in So the Drama, when Ron prevents Drakken's escape, incensed at him for using Bueno Nacho as a pawn in his "L'il Diablo" scheme. Drakken actually fears for his safety, knowing full well that Ron is capable of beating him up if he wants to, and Ron even managed to get him to finally say his name, although after that he forgot his name as always.
Ron displayed arguably his greatest example of monkey kung fu in his battle with Fukushima. Throughout the episode, Fukushima taunted and humiliated Ron referring to him as "Outsider" and constantly tried to cause him injury. During the first encounter between them, Ron was able to hold his own in a staff sparring session between them. In the second, Fukushima's blows constantly missed the dodging Ron who used his famous leg twist to bring down Fukushima, catching and flinging him when he launched himself at Ron and finally causing a minor earthquake with his Mystical Monkey Powers to bring down icicles and trap Fukushima taunting him with "It was my honor to defeat you!"
One of his 2 main foes is his childhood bully Gil Moss. During their time at Camp Wannaweep, Ron, afraid of the polluted water in Lake Wannaweep, allowed the bullying Gil Moss to have his turn at swimming time in the lake, while Ron took Gil's arts and crafts sessions. The extra time Gil spent in the lake resulted in him transforming into a hideous sea monster, Gill. Ron has battled Gill twice, once alone and once with assistance from Kim, each ending with Ron victorious. The second continued a series running gag of Ron being transformed or altered, in this case being mutated by a toxic lagoon off of Lake Wannaweep into a large man-beaver. While Monkey Fist has some small grudging respect for Ron, Gill has only disrespect and hatred, referring to him dismissively as "Ronnie" or "squeeb". Although Monkey Fist is credit as his arch-foe, Gill is the only villain who has a desire to get revenge on Ron.
While hardly a major villain in the series as a whole, Jr. and Ron have gotten into physical confrontations on more than one occasion. Mostly, these face offs were about minor things, like hair combs or parking spaces. Still, despite being so muscular, Jr. is one opponent that Ron has surprisingly proven to be a physical match for, even without Ron's Mystical Monkey Power assisting him. However, none of their "battles" have ever resulted in a clear winner, mostly because their conflicts have ended up being cut short by third parties.
Arguably, these two can be considered arch-foes of Ron's after they make the critical mistake of threatening Kim's life in his presence. Realizing that he is about to lose the most important person in his life, and aided by Sensei's encouragement through a vision, Ron taps into his Mystical Monkey Powers to take on the aliens. This time he has full control of his powers and is rendered unstoppable. In the end, he tosses the two into their crashing spaceship, causing a huge explosion that presumably destroys them, although that was unconfirmed. This is also the second time in the series after Monkey Fist that an enemy appears to have been killed by a main character.