mtg leinore commander deck Ultra Pro put a +1/+1 counter on up to one target creature you control Leinore, Autumn Sovereign - leak

With four of these in your arsenal, you could mill almost half of your opponent's 60 card deck, and for a low cost as well

The Lord of The Rings: Tales of Middle-Earth [Epic Adventure, Legendary Characters, Tolkien Magic] This deck lets you bring the world of The Lord of the Rings into your Commander games

They have quite a few cards on this list, and many others that would be great contenders

Umaro, Raging Yeti* Straight to you from the World of Ruin in the Revival Trance Commander Deck, Umaro is a beast of a design as a 6/6 for 6 with trample who will either pump your board, shoot something, or wheel you each turn at random

From there, its just tons of tomfoolery with spell and permanent switching

There were a few people who were open to doing something with Jeweled Lotus now, but that was not the majority opinion