I love "The Cerebral Assassin". It just sounds badass and described early to mid 00's Triple H to perfection. "The Game" was also an excellent nickname and it didn't come across as being forced upon HHH. It just came naturally.
"The Texas Rattlesnake" and "Macho Man" would probably be in my top three along with the "Cerebral Assassin". "Latino Heat", "Rated R Superstar", and "Big Poppa Pump" are awesome as well.