Best acting performances you've seen so far?

A couple really memorable ones for me were Wu Lei in Love Like the Galaxy (especially the revenge scene) and Lee Joon Gi in Flower of Evil.

Yeah those are super good.

Mine would be the Mom in Beautiful World. It's always is so heartbreaking and inspiring 

1. Park Earn Bin -Extraordinary Attorney Woo
2. Son Ho Jun - Go Back Couple
3. Yoo Seung Ho-I'm Not a Robot
4. Seo Yea Ji-It's Okay to Not Be Okay
5. Apo Nattawin Wattanagitiphat and Bible Wichapas Sumettikul-KinnPorsche
6. Kim Jung Hyun-Kokdu: Season of Deity
7. So Ji Sub-Oh My Venus 
8. Lee Jong Suk - W 
9. Kim Hae Sook and Kim Hye Soo -Under the Queen's Umbrella
10. Raiku-Life: Love on the Line (Director's Cut)

In no particular order and too many to choose from but these are the most memorable to me so far for their preparation for the role and the emotions that they make me feel (good or bad)

• Ji Sung - Kill Me Heal Me
• Lee Joon Gi - Flower of Evil

But really, I just get impressed when I watch several of one actor's works back to back and the characters in each are very distinct. At the moment, thanks to Goblin, Gong Yoo and Lee Dong Wook are on my radar. The former through a comparison between his role as Goblin and the MC in Train to Busan, more so given they released in the same year. The latter between his role as Reaper and the secretive uncle in A Shop For Killers which I just finished binging this morning.