I'm gonna have to say probably Helga. The way she was head over heels over Arnold and kept things mostly to herself and her diary reminded me so much of myself when I was 4th grade. Plus, her distant relationship with her parents, even though I have always been very close with my mom moreso than my dad. I could also relate the fact that she was always craving for that love and attention from Arnold, but very discreet with her feelings. The only difference is I never tried to act all mean to the person I had liked just to disguise my true feelings inside.
Helga- having crushes in 4th-8th grade and admiring them from far cause I was scared to do anything about it. I wasn't a stalker like her though. Lol
Arnold (in the earlier seasons)- A normal well-behaved kid who's nice but occasionally gets into mischief like all kids do at age 9. This doesn't apply to later seasons when he basically turns into an "adult" in a kid's body.
Patty- We both speak the truth and tell things like they are. We're both genuinely nice to people who respect us, and low key want to beat the sh!t out of people who don't.