Superman Dynasty by far. Imps are included in the dynasty outside of the direct imp bloodline. Also the Dynasty likely outnumbers the number of lanterns there are.
While there isn't any indication of how many members belong to the Superman Dynasty, or how powerful most of the members are, we do know that they come from all periods in the timeline and there are, at least at some points in time, at least several at once.
I'd guess that if you took them all together, they'd greatly outnumber the Green Lanterns. Even if they didn't, members like Kal Kent and Titano could probably take on a hundred+ random GLs at once. Most of the members supposedly have 5D Imp heritage, so they've got to be boss.
If we allow the Superman of the 5th Dimension in on this fight though, things go sour real fast for the Lanterns.
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"And then there was nothing. A once broken something now void.
And on the first day, Doom spoke... 'Be.'
And then there was life."