The best feeling is when:
- as
, you ult-smited a kill on an enemy combined with URF icon finisher (the red one like that Panth smite in login screen ), especially if it's a 
http://i3.kym-cdn.com/photos/images/original/000/133/830/1307793940001.png
- when you nuked an enemy with a single
spear
http://i3.kym-cdn.com/photos/images/original/000/133/830/1307793940001.png
- when a retarded toxic dude starts harassing you, and then after the game ends, you made an awesome comeback at him, and after you left he constantly tries to add you just to fight back
http://i3.kym-cdn.com/photos/images/original/000/133/830/1307793940001.png
What about you guys? Anything you like to share to make you feel good? :3
Note: "It Felt So Good" meme in comments are COMPULSORY. Or else, it doesn't look so satisfactory ;)