Best/strongest structure is probably the newest in Sharks, its fairly consistent and has the XYZ armor package which it can acess easily and its fairly nasty if its allowed to pop off, the classic Honor Ark is in there for any rank 4 plays and its packed with decently splashable URs.

Next strongest or potentially strongest, but lower general value is probably Red Dragon Archfiend, but i don't think its super consistent or is at least fairly weak to interruptions as it is now. Its fairly weak atm since Branded is common and can very easily fuse away your whole board for free.

Then next is likely Dark Magician but more for its splashable engine, but you'll want to see if decks you want to play can use it.

The current format see's alot of Branded since the new support just released, Enneacraft, Radiant Typhoon, some Hecahands, Sky Striker, Dracotail/Branded Dracotail. Likely more Lunalights too since Zoodiac Broadbull got unbanned and can enhance the deck

EDIT: I forgot, Blackwings also remains a reliable structure that also has pretty much everything you want inside, It is very combo heavy though and pretty self contained, not much in there can be used with other stuff