Best Undead to Create?

[sambouchah]

What are the best undead to create as a necromancer? I'm thinking of becoming a good lich in our current campaign and I'll have Create Undead on my spell list at that time. So what undead(not stated in the PHB under the spell's description)?

I like the Plague Walker and the Necrosis Carnex but I feel like they aren't the best I could create. Thoughts?

Thanks for any help!