I love timers and challenges.
Some of the most memorable moments have been from close races to finish. Downing the final boss with mere seconds remaining.
I also enjoy DBM tracking boss kill times. It’s cool seeing how many times I’ve done a boss and if I set a new personal record ect.
Or when I started farming the Underot mount. Seeing how fast I could clear the dungeon. I saw the world record was like 3-4 mins (for the whole dungeon!)
Or when I played classic. Going for fastest boss kills or fastest overall clears of MC. It made things fun and exciting compared to what would have been a boring and slow raid.