In a multiplayer environment, getting to steal an opposing Commander is sweet
Howling Mine is the grandparent of them all, having seen the light of decks back in Alpha , and it does have an interesting catch that not all later iterations have: You can turn the hugs on and off, as long as you have ways to tap or untap the artifact as needed
I started with an Angel of Serenity in my deck
White-Blue is all about "modified" creatures, which means lots of equipment, aura enchantments, and +1/+1 counters plus some creatures designed to take advantage of them
Gonti purists might want to stick with the aetherborn, but Black Cat is an option for people trying to go bigger
I do prefer the Entomber to the Grave a bit as it's on a body that can swing, block, grab a piece of equipment, and it has deathtouch so it can trade up like Acidic Slime