There's no real way to tell their strength against each other, without referring to the useless measurement of power levels, which I don't use. Therefore, I just chose Gogeta... just because.

If we apply GT, Gogeta by far. But if only by Z, then Vegito. Why? Vegito toyed around with Super Buu Gohan Absorbed, who was stronger than ultimate gohan, who was stronger than ssj3 Goku. Gogeta isn't stronger than Super Buu Gohan Absorbed, possibly stronger than Ultimate Gohan, probably stronger than Ssj3 Goku, at the very least on par. Therfore, i believe Vegito is stronger.

Vegito can go Super Saiyan God Super Saiyan.

They already said in the show Potara fusion is stronger than the fusion dance fusion.

If you were to say strength, Vegito is stronger because power levels must be equal for fusion dance which that rule doesn't apply for potara. However, Gogeta's attitude would make him win in a fight (IF WE TAKE AWAY TIME LIMITS FROM BOTH). Ppl are gonna say "oh what about ssj4 Gogeta, he was just as goofy" keep in mind that it was ssj4 Vegeta fused with Kid Goku (ssj4 in Goku's adult body). Goku as a ssj3 (adult goku) was much more serious than Goku as a ssj4 (kid goku with adult goku's body). Vegito is filled with cockiness and over confidence (which was shown in Buu saga and future trunks saga) which are vegeta and goku's downfall in dbz, examples are when vegeta allowed Cell to absorb 18 to have a proper challenge and when Goku dropped his guard against frieza in Revival of F thinking that the battle was over. Gogeta is different, Gogeta is filled with Goku and Vegeta's anger which were the reasons why they were able to overcome many challenges such as Goku achieving ssj for the first time and defeating Frieza or Vegeta getting revenge and destroying Goku Black until he powered even further. It would be a close fight but I really don't see Gogeta losing with the fusion reborn attitude. Well these are my thoughts.