Honestly I can't say.
Darkseid or Metron or Doom would be more clearcut opponents for Thanos. TAO is either the smartest character in comics or the most overblown since I can't recall him doing anything that was that amazing. Of course I'm not that into Wildstorm. Most of the time with Wildstorm I get the feeling they're the Image Comics of the 21st century, "We make comics that are so badass that after reading them your girlfriend will get pregnant! Our characters are like DC comics characters except more buff...and edgy...and badass...and buff...and cooler costumes...and more buff!"
Originally posted by Omega Vision
Of everything he did the only real feat was outsmarting Majestic who while a genius isn't quite as smart as Thanos. I'd put Majestic on a similar level to Tony Stark intelligence-wise.
Mr Majestic is smarter then Tony Stark his intellectual abilities such has logical thinking, creativity and reasoning is beyond the scope of human intelligence. Despite the fact that Tony Stark is a genius and able to make advance in other scientific fields his intelligence is still in the human range.
Mr Majestic has computers that allows him to tap into other computers from different alternate earth.
Originally posted by Bouboumaster
Thanos.The dude is some MILLIONS years old, outsmart nature itself (Galactus) and a dude who his only purpose is being smart (Grandmaster).
The guy's a genius but on a cosmic scale.