zopzop
Lord of the Great Abyss
IMHO, using current versions for both characters, I'd give it to Zeus but Thanos would give him hell.
I wouldn't have said this but recently Zeus' stock has risen. Pre Pak, I'd actually give Thanos the win after a prolonged fight. Don't believe me? Check out Zeus' fight vs the East Coast Avengers in the late 80s.
Pak/Post Pak Zeus is another story. During the horrendous Fear Itself garbage, in a Journey into Mystery FI tie in, Zeus and Odin were "debating" forcefully about what to do with the the whole Serpent fiasco. Zeus only backed down after the other All Fathers took Odin's side and judged that the Serpent crapola was an internal Asgardian issue. That right there tells us Zeus is in Odin's league power wise, or else Odin would have walked all over him.