These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Crowning Moment of Heartwarming: Former Arsenal striker Eduardo who is now at Shakhtar Donetsk after a career blighted by injury. He returned to Arsenal Stadium with his new club in this seasons group stages, not only did he get a standing ovation when he came on, but he capped his return with a goal that was celebrated by the Arsenal fans as much as an Arsenal goal. True to his word before the game he did not celebrate the goal as well.
Didier Drogba comforting Bastian Schweinsteiger after his missed penalty in the 2012 final may also count.
After the 2013 UEFA Supercup final, several Bayern players comforted Romelu Lukaku, after missing the penalty against Bayern Munich.
Just watch Bayern Munich's squad after the final whistle in the 2012-2013 Final. Arjen Robben standing with his arms out stretched and tears pouring down his face in front of Bayern Munich's supporter's section while they chant is enough to choke any football fan up.
Did You Just Punch Out Cthulhu?: The 2013 Champions League semi-finals saw Bayern Munich defeating FC Barcelona 4-0. The next day, Borussia Dortmund trashed Real Madrid 4-1.
Not to mention that this happens every time, when a perceived underdog beats a favorite team.
Earn Your Happy Ending: Bayern Munich, after suffering humiliating defeats in the 2010 and 2012 finals (that of which actually took place in Munich.), finally won the tournament in 2013.
Bayern Munich midfielder Arjen Robben missed a possible game winning penalty in the 2012 competition, conceding the final to Chelsea. In the 2013 final, he scored the winner, and received a large amount of cheer from the Bayern supporters.
Hype Backlash: Since 2003, there has certainly been some of this applied to Real Madrid, and Arsenal have suffered from well before that.
Arguably the Group Stage suffers from this as a whole.
Team Tiers: A curious case, being real life, but reputation and money leads it to being true. Only a few teams are likely to win - the "Big Four" of England, Barcelona, Real Madrid, Inter, AC Milan, Juventus and Bayern Munich.
To elaborate, in the past 15 years of the competition, the only winner not from the above was Porto in 2004, and the only runners-up not from that list were Leverkusen in 2002, Valencia in 2000 and 2001, AS Monaco in 2004, and Borussia Dortmund in 2013.
Too Soon: Played matches on the night of September 11, 2001. Realized the insensitivity of this and cancelled the matches on September 12, 2001.
Cowboy Bebop at His Computer: In a very tragic example, some media picked images of Galatasaray fans celebrating their victory against Juventus that day and presented them as if they had been celebrating the attacks on the U.S.
The Worf Effect: Barcelona were this to Bayern Munich in the 2012-13 Champions League Semifinals.