Actually (wow this is going to sound so nerdy) when Gohan, Krillin, and Bulma are on the Namekian Spacecraft headed to Namek. Krillin makes a comment about Gohans clothing (the namekian clothing piccolo gave him). Krillin said something like "Oh it looks like you really respect Piccolo huh Gohan" Gohan then replies by saying "Yeah I respect Piccolo as much as my father." And to point out something else! When Piccolo is dying when he gets in front of Nappas blast he tells Gohan how he was like a Best Friend to him and how Gohan was the only person he ever cared about.