1. HE DIDN'T READ THE LETTER. Mind blowing, really. He and Rachel finally decide to work things out and she puts everything into a long letter that he doesn't even bother reading. 

2. Because Chandler and Joey are superior male characters in the show and that's obvious.

3. "We were on a break" should have been Ross's catch phrase in season three because he said it so much. He and Rachel were broken up for hours, I repeat-- HOURS, before he drunkenly turned to "the girl from the copy place." 

4. He makes people refer to him as Dr. Gellar... are you kidding me?!

5. When he wouldn't help everyone when they were stranded on the way to Rachel's ski house. Once again, he was being petty that his friends chose to spend time with Rachel after they had broken up. If your friends car breaks down, you go help them... no questions asked!

6. The way he tells people to F Off.

7. When he wrote a "Pros and Cons" list about Julie and Rachel-- are you kidding me? Writing down their flaws to choose between them is the worst idea. Also we can all agree that Julie sucks, but her con being "not Rachel" is a really awful thing to write about someone you're dating.

8. That one time he decided to get a spray tan and it went terribly horribly wrong.

                

9. He's a cheater. Ross cheats on the bald girl (Phoebe's friend), Julie, and pretty much Emily with the whole wedding thing.

10. THE WEDDING THING. He says Rachel's name instead of Emily's at the altar. Do I need to say anything else?

11. When he rubs in Rachel's face the fact that Chip (Rachel and Monica's high school crush) called to go on a date with Monica.

12. Phoebe's Cat. When he doesn't support Phoebe that time she thought the cat she found is her "mother's" spirit reincarnated. If your friend thinks her mother is a cat, you support her!

13. When he lies to Rachel about their marriage being annulled...but they're actually STILL MARRIED. All because he doesn't want to get a third divorce, selfish selfish man.

14. His constant grammar corrections-- "Whom?! Whom?!" SOMETIMES IT'S "WHO," ROSS!

15. When he complains EXCESSIVELY about his coworker eating his leftover turkey dinner sandwich. We get it-- it was good, but the tears were overkill. 

16. He made the biggest deal about not donating money to the Handy Man's retirement fund because he had only recently moved into the building. If you aren't going to donate money, then shut up and don't go to the retirement party... and while you're at it, don't cut the cake before they've gotten a chance to present it to the person that it is meant for... obviously.

17. Guilt tripping Joey, Chandler, Monica and Phoebe when they hang out with Rachel and not him. Sorry, breakups are hard, but thats not reason to put your MUTUALLY SHARED friends in the middle of it!

18. Finally, everything about this GIF.