Favorite brick in your collection?

My personal favorites are these chrome silver 2x4 bricks from the 3026-1 25th Anniversary Tub from 1998 and the yellow Duplo ‘Made in Connecticut’ 1x2x2 brick that I got from the Big E Convention way back in the day. I always thought the silver bricks were neat, and as a kid they were always central to whatever storyline I was making. And I’m from Connecticut so I just think the Duplo brick is cool lol. But now I’m curious as to what other people’s favorite bricks would be, and why? Be it...