Picking just one is hard. There are plenty of color combinations that I wish had better distribution of commanders- Abzan especially.
Green is the only color I really like regardless of my deck's distribution. For instance, I really like White, but only when it's the dominant color or at least around 50% of the deck (my Sigarda deck is heavy white). On the other hand, I vastly prefer less blue to more blue, preferring it mostly as a third color or a support color (not that lots of blue can't be fun, I just don't tend to build a deck that way.)
Oddly, I love Izzet despite treating both Red and Blue like "supporting" colors rather than colors that can stand on their own.
I love Sultai but I don't look forward to building Simic (there's a lot there that could be done, but not enough legends or support for the really interesting stuff like manifest). Dimir and Golgari are my jam, but the Mimeoplasm deck is largely supported by the Ezuri precon, so it's more that the addition of black and the fun commander help a ton.
Abzan needs a good commander. Some of them are fun, but none of them really speak to me in terms of wanting to build them specifically.
Nathaniel Stewart
Playing him as a durdle deck is fun but not very good. Playing him as combo wins a lot more, but it isn't very fun.
Isaac Hall
Any spicy tech for serra ascendant a 6/6 flying lifelink for 1 white mana?
Explain why mental misstep isnt spicy and is infinitely times worse than serra ascendant
Luke Mitchell
He's literally my best deck. Get yourself an Ashnod's Altar, a Hero's Blade, a Zulaport Cutthroat and/or a Blood Artist, a tutor or two, and then build literally whatever you want around it. I went for a mix of Red threaten effects, Black reanimation, and sack outlets in both as a starting point, then slowly put in some real potential. The best part about it is, I still kept in plenty of pet cards ala Kurkesh, Pyxis of Pandemonium, and Fated Return, and it doesn't hurt the deck nearly as much as you might think.
By sheer nature of Grenzo's design, you will have artifacts on the field. Ones that can scry and ones that can stick graveyard cards on the bottom of your library. You'll then have sacrifice components with Altar, Zulaport, and Blood Artist. It seems like a lot, but you'll have at least 20-30 free slots to fill with pure Rakdos goodstuff.
Gabriel Powell
Try this spicy tech son it's straight sriracha!
Robert Martin
And now, Daretti2 can play too.
Ian Fisher
Durdle Grenzo is both not very fun nor something I've seen much of. Mine runs a couple combos and is otherwise straight beatdown, but he can be tuned to focus on voltron, combo, or durdle as desired, and can probably do all three at once with the right build.
The only problem I have with his combo is how slow pinging everyone for one is, and the fact that it's not the kind of thing you actually scoop to- it's not infinite. Combined with the stuff that's in Standard at the moment, though, you can probably take out problem players directly with faster combos while you ping everyone.
Charles Moore
I wish I were a don but there's no evidence of any touching going on with Johnny or Timmy. Also pay me.