Octavia for sure! Not only is her toolkit good at basically everything, her passive helps with one of the worst early game problems, energy economy. Not being forced to rely entirely on energy drop RNG to be able to maintain your abilities is liberating before Zenurik and other energy generators kick in.
The main thing that makes Wisp such a good support frame is her sheer convenience and low maintenance. Support is a very unpopular and underplayed role in Warframe and for a good reason. All the good top end frames are entirely self sufficient, requiring no external aid to easily dominate. Wisp breaks the mold by providing generally useful buffs that apply to you AND your teammates while requiring no work from the player on top of having a solid CC/damage ability and a free subsume slot. A 400% power strength Wisp with Pillage makes for an incredibly nasty weapons platform frame while also helping out teammates with her Motes. She can support her teammates without needing to work for it all while being capable of doing the mission by herself if need be.