Ross Geller is the classic "nerd" character in Friends, except he gets to hang out with people who were actually cool in high school (presumably). His social awkwardness isn't off-putting as much as it is uniquely charming — explaining why he still manages to have a number of relationships and marriages over 10 seasons.
On the other hand, Ross can get tiresome when it comes to "being right," a feature that is ironically derived from his own lack of self-worth. He can be jealous and insecure over nothing or let his ego get in the way of his friendship. It's a good thing that everyone loves Ross because he would otherwise just be troublesome.
Good Friend: Thanksgivings With Chandler
Through various flashbacks, it is seen that Ross and Chandler spend a lot of Thanksgivings with each other, and always at the Geller house.
This is largely because of Chandler's problem with his family and how they behave towards him, but especially because it's when the Bings finally announce their divorce — permanently associating the holiday with misery. It's truly a comionate offer on Ross's part, although it must be noted that he doesn't really have any other friends he could take over.
Awful Friend: Frames Chandler To Hide His Marijuana Habit
When Monica and Chandler plan to reveal their dating status to her parents, they hit a dead-end, mostly because it seems that the Gellers have an abiding hatred of him. All of them are stumped until Judy Geller snidely comments that Chandler might be "stoned again," which reminds Ross of what he did when he was in college.
He reveals that he had almost been caught smoking weed in the dorm room that he and Chandler shared, but at the last minute, he decides to pin the blame on his roommate. Thank god this faux pas is caught in time.
Good Friend: The $100 Spending Limit
Ross and Joey spend a few minutes alternating between who should date the woman they've both been seeing, Kristen, until they come up with a watertight plan: Both of them take her out once and then let her choose. A fair solution, except for that Joey mentions that his financial situation discludes any kind of big spending, and so he asks if they can set a limit on how much they spend on the date.
Ross accepts the conditions, albeit grudgingly after Joey threatens to "do what [he does] on dates," and then presumably lends his friend $94 as the latter only has $6 to his name. It's a sweet gesture that ultimately does not pan out in the end.
Awful Friend: Almost Destroys His Relationship With Joey
During their "vacation" in Barbados, Rachel and Ross are both upset because Joey and Charlie are together at the time. The former both get what they want before going home, though. Ross kisses Charlie, a terrible move because everyone knows how sensitive Joey is about these things.
On the other hand, he manages to save the situation by confessing about what happened, which Joey surprisingly doesn't seem to mind. This, of course, is because the latter kisses Rachel (and comes off as the worse friend because he doesn't divulge this tidbit to Ross).
Good Friend: The Disposable Wedding Cameras
Chandler believes that he has somehow lost the cameras used for his wedding with Monica, which would have set a good precedent for his marriage. Ross convinces him to fake the whole wedding again — and so both of them obtain a bunch of disposable cameras and gatecrash a reception.
Here, they start clicking photos of the scene, completely oblivious to the fact that the Geller-Bing wedding involved more than just the two of them. The plan ultimately fails because Monica has had the cameras the whole time, but this Ross and Chandler chummy misadventure is certainly one for the books.
Awful Friend: Overenthusiastic Science Education
Phoebe mentions that she does not believe in the Theory of Evolution, which is all the ammunition Ross needs to go off on one of his science rants. He takes it to heart and promises her that she will understand how it works, sooner or later.
Ross does actually offer her a ton of useful information about the subject, but Phoebe simply dismisses everything he says. Thankfully, she deflects the argument by telling Ross that he has an "obsessive need to make everybody agree with" him. And she's completely right.
Good Friend: A Bicycle For Phoebe
Ross and Phoebe have had some intimate moments as well, like when she tells the group that she never grew up with a bike. She mentions that a neighbor girl had an incredible bike of her own: "pink ... with rainbow-colored tassels hanging off the handle-grips," so Ross goes and buys her a near-identical one.
Hearing Phoebe thank him "for the best present [she's] ever gotten" is more than enough, and he's a great friend in this moment.
Awful Friend: "You Don't Kiss Your Friend's Mom!"
Ross gets smashed on tequila, before proceeding to discuss his various issues with Nora Tyler Bing, Chandler's mom. The scenario, precarious as it is, devolves into the pair of them sharing a kiss (which would have gone unnoticed if not for Joey).
The latter then screams at Ross about kissing his best friend's mother, although he's partially upset that he has never kissed Mrs. Tribbiani. In the end, Ross has no choice but to come clean, which leads to a furious Chandler.
Good Friend: Purchases Pat
Joey has had Pat the ceramic dog ever since he lands a new job as a soap opera star, but when his character is to be killed off, he realizes that he doesn't have much money saved to tide him by until he gets a new role.
Ross tells him to try auditioning for minor characters, but Joey is far too conceited to take what he believes to be a step down the acting ladder. Although he loses most of his worldly goods, Ross decides to spend $200 to retrieve Pat for his friend.
Awful Friend: Being A Terrible House Guest
After his divorce from Emily, Ross ends up homeless, so he asks Chandler and Joey for help. The two of them are happy to welcome their lovelorn friend into their apartment until it turns out that having Ross around all the time is extremely annoying.
He not only insists on having a noisy air purifier, but he also fills their home up with his stuff. One of the final straws is when Ross changes Chandler and Joey's answering machine message to a terrible rendition of Queen's "We Will Rock You."