No... Jay is right. Mystic Gohan IS the strongest non-fused character in all of DBZ. He was obviously screwed over because Toriyama wanted to make Goku the hero.

Just throwing this info in, GT is not part of the main series and doesn't count by the original manga author, and therefore the strongest form is Super Saiyan God Goku ATM, though he was infused with powers from 5 other pure heart Saiyans. Just saying.

mystic gohan is the strongest. The japanese fans did not want gohan to become the hero so toriyama had goku defeat buu instead.

On topic, Kid Goku and Teen Goku was the best. After goku turned into a super saiyan he became to serious for my liking - he lost the childish charm although you see it on occasion it just isn't the same.

Another point that's important to mention is when vegeta embrace for the first time that goku is better than him, vegeta realized that his power source was coming due to the desire to push his limits every time he fight someone that is better than him and not for the pleasure of kill or world/universe domination, vegeta thought at first that his power was coming for protecting his family but at the end of buu saga, vegeta was in the same situation so he notice that wasn't the case with goku.

@Jaywood
I kinda disagree with you, considering that I have watch the series for almost 14 years in 3 different version: English/American version, Spanish/latin version, japanesse/English subtitles, and in my opinion the worst case scenario is that both are equally powerful with a fair advantage to gohan due to the abilities to better control the energy/stamina in that stage vs. Super saiyan 3 require a huge amount of energy to control in order to keep the transformation. Let look at the fact, kid buu was stronger than super buu, just have to look at goku and vegeta faces when super buu transform in kid buu, they thought that the height of kid buu would give them the advantage but later on, they were realizing that kid buu was increasing his power at every second giving them the hint that buu wasn't fighting seriously, so in other words, we never knew the depth of the kid buu power. Gohan never fought kid buu so we never know their power differences and goku was able to keep up with him with only having the disadvantages of stamina drain. Also Kid buu was the most evil of all so this would prevent to hold back his power.