At first I thought Grimmjow but when I think about it, its a closer battle than that.
Grimmjow's only edge is ranged attacks which is null since Grimmjow is not one to keep distance in the first place. He's going to need to start released to pose a threat as well. Even then, Sanji is going to dominate when it comes to close quarters due to all around better speed, destructive capacity, and durability. And I doubt Grimm is tanking a multi-city block+ kick which could be far more devastating than a AoE attack of similar dc (like getsuga tensha), given it's concentrated in a much smaller area (his shin). Grimm could survive one but not tank one, not to mention the additional intense heat from diable jambe.
Grimmjow has shown multiple times that when an opponent is sweating him he will go ranged(Ulquiorra, Shinji, Ichigo 2nd and 3rd times) In fact he has only had 1 fight where he didn't really use any ranged attacks and that was his first confrontation with Ichigo. If Sanji really makes Grimmjow he will have to deal with a endless array of ranged attacks. Not to mention BFR isn't restricted so even in the instance Grimmjow doesn't win, he could use Caja Negacion to BFR Sanji.
Bump, to repeat what I said before in the last thread.
@ALMIGHTY: @Captivated: @luthluth: @DXC: @HungryWorld: @Zerrathe:
Not saying this changes the tide of battle or anything but I people seem to like to bring up Sanji breaking his leg on Vergo and doing minimal damage to him, but also forget that:
1. Sanji did not use anything except his most basic attack (No Hell Memories, spectre, hachi hash ect.) In addition, Sanji never used his haki in that fight, I mean even Vergo used Armament haki for his attack at the end.
2. The reason Sanji was doing little damage and got his leg snapped was because Nami had already messed up his body from the previous body swap done by Law. (Similar to how he fought Jabura back in CP9 after getting seriously hurt by Kalifa)
That fight was not a good way to determine superiority between the two. Both fighters did not use all their arsenal, Sanji was already injured previously, Vergo retreated first.
Besides not long after Sanji charges at Doflamingo and lands a kick as well and Doflamingo is>>>>>>>Vergo, granted if not for Law Sanji would be dead, however he didn't break his leg in half on someone like Doflamingo and even he has to get defensive once Saji used hell specre.
Buuuuuuut, Sanji still loses this for now low-mid diff.