Based on the 6 movies:
I do not know what you mean by "greatest", but it is definitely not "best in a fight" in my opinion (based on Obi Wan have the most votes).
From ep. 3 we know that Obi Wan had no chance against Sidious or Count Dooku (Sidious: Yoda said that - Dooku: we saw that in two fights)
Yoda is at least as good as Sidious and probably better than Dooku.
Anakin is better than Dooku.
It looks like Windu was better than Sidious, though it may have been acting from Sidious (personally I am not convinced - It looks like that if Anakin came just a few seconds later Windu would have killed Sidious)
The above convince me that Obi Wan is not even in top 3.
Obi Wan did win against Anakin, which was a big mistake from Lucas. At that time Anakin was lot more powerful compared to Obi Wan. The fight should have been before Anakin was powerful or something else should have happened to Ankakin. Personally I found the fight ridiculous and hate it - no logic in Obi Wan could beat Anakin.
Based on the movies Yoda is probably the best Jedi. Luke may also take the title. I vote for Luke, but is actually more for Yoda now. Luke has the potential for being the greatest, but he did not reach it in the movies, though he became powerful in the end of ep. 6.
of course his defense was better, thats what his form was...but it doesn't matter, Anakin is better at sabers period...no grey area here.
smarter--you cant compare the two's intelligence as its never really semonstrated. But OB1 thought he could help Ventress, Anakin knew better, and if you want o bring up 4-6, i think it'd be safe to say Vader was EXTREMELY intelligent, and as i recall...HE LIVED. For me, I don't know, that counts for alot. Anakin was just just stupid during his his fight with OB1, and even thats not his fault due to lack of intelligence, he was in a ball of confusion and his mind was torn.
and you don't need spelling lessons...we have spell check.😉