Which decks leaving with rotation this autumn are you sad to see go?
For me there are two big ones: Rakdos Anvil and Mono-Blue Cauldron Combo.
Rakdos Anvil has been able to turn into Mardu Warleader's Anvil, which can kill out of nowhere with Ojer Axonil. It's a lot of fun to play, but yes not a tier one deck at the moment. Gets wrecked by Temporary Lockdown, unfortunately; but still does alright if not great.
Mono-Blue Cauldon Combo is, in my opinion, more consistent than the GU Culdron Combo that remains. It can be surprisingly aggressive as a plan B in case oppo is focused on disruption, and with new additions from MKM (Forensic Researcher) and OTJ (Harrier Strix) is more powerful and consistent than even. Does very well on ladder, but is a bit of a hassle to play on Arena, because infinite mana isn't handled well at all. That might be why it seems unexpected and steals a lot of wins. Doesn't actually get wrecked by Temporary Lockdown, because you can bounce it at end of turn and get all the combo pieces back and then just go off.
But what about all you other Standard Appreciaters? What decks are you sad to see go at rotation?
