I have to give this to The Doctor. Skasis Paradigm rivals most of what Rick can conjure up. So far, I have not seen Rick create anything that can Reality Warp or withstand it.
Also, side not/fun fact: The creators of Rick and Morty said that they will never use time travel in the show as it is an over-saturated concept. So given that, I doubt Rick would resort to time travel, even though he is very likely to be able to use it.
Doctor does not even need preparation, even because with preparation Rick proved himself to be only Infinite Multiversal (with quote, without, just universal), while Doctor with only the TARDIS is already dimensionally transcendental (saying that several times, it would probably be TARDIS with all his power released), which Rick has never even gotten close to or will even reach.
The Doctor, definitely. You said no Eye of Harmony nor TARDIS merge, but you never said GLORY...?
Yeah, Glory Doctor trumps. And plus, The Doctor has time travel and Rick doesn't (Justin Roiland specifically stated in an interview that they wouldn't be adding in time travel to the show as it would make it too complex).