Gohan idolized his father from the day he was born, even though Goku wouldn't always be #1 papa material (in my opinion at least [ahem]). He also loved his mother a great deal, despite her strict all-work and no-play policy. Kuririn was a close friend to him as well. But Gohan's favorite person to hang out with is most likely Piccolo (duh).
Even though Piccolo had abandoned him for months to survive in the harsh wilderness, Gohan saw him as much more a friend then threat. Whenever he was punched into a river or fried with eye lazors, he simply brushed it off. In battle, the child ended up crying because he'd been too afraid to blast Nappa. He couldn't take letting his mentor down.
Throughout the entire series, Gohan gets his tail saved by the surly namek he calls his best friend. He ends up idolizing Piccolo just as much as, if not more than his father. In the end, Piccolo gets killed as Earth erupts. We see Gohan immediately break down in tears (keep in mind, he's grown and the father of a 14-year-old) and fall to his knees as his friend and mentor explodes with the planet.