Usagi and her Kid from the Future Chibi-Usa both wear their hair in exaggerated odangos in Sailor Moon. So does Queen Serenity, Usagi's mother... in a past life. The parody manga Parallel Sailor Moon introduces the daughters of the four Guardian Senshi, who look exactly like their mothers (hairstyles included) and have the same names.
Goku's younger son Goten from Dragon Ball has the same exact hair as his father, who has the same hair as his father Bardock. Likewise, Vegeta and his father, King Vegeta, have identically ridiculous hairstyles. It also has a rare cross-gender example in Dr. Briefs, his daughter Bulma (when not permed), and her son Trunks. The Non-Serial Movie explains Goku and company's hairstyle as belonging to a particular genetic type common to Saiyans in Bardock's (original) power level, as unrelated character Turles is shown to have the exact same look as well.
Yu-Gi-Oh!: Yugi's hair spikes are inherited from his grandfather, though this is less obvious until the chapter where we see Sugoroku as a young man.
The Armstrongs in Fullmetal Alchemist all have blond hair with a distinctive curl in the front. Edward and his father Hohenheim both have the same shade of blonde hair that they both wear in a very similar style.
The eponymous Yaiba seems to have inherited his hair from his father.
In Nichijou, Nakanojou and The Daifuku Guy have mohawks.
Asem, the second-generation protagonist of Gundam AGE, has a more masculine version of his mother's short haircut + ponytail.
In Marginal Prince, Joshua's hairstyle is exactly the same like that of his father, with the color of his mother's hair. At the same time, it looks identical to that of his ancestor, King Alphonso. And then there is Henri, whose hair has the exact same color and style (including length) as his dead mother's.
Also, to a certain extent, all members of the Kurumi family sport wavy hair.
The Lyrical Nanoha franchise has an adopted child version with Vivio, whose Older Alter Ego shares the same side-ponytail hairstyle as her Nanoha-mama. She'd wear it in child form too if she could, but the Nanoha Strikers manga showed that all that concentrated hair causes her to tip over to the side. However, Vivio has the same Girlish Pigtails as Nanoha when she was a child.
Naruto has basically the same hair as his father the Fourth Hokage, but has his mother's face.
Il Sole penetra le Illusioni: Akari and her mother Hinata don't have the exact has hairstyle, but they both have this odd hair-crescent thing. It sounds weirder than it looks.
In Katekyo Hitman Reborn! Tsuna, apart from inheriting the same powers, also has the same hairstyle as his ancient predecessor Giotto.
Lucky Star: Konata and Kanata Izumi also are a clear example of this trope; not only do they have the same hairstyle but they also share the same hair color. Well, with the exception that the daughter additionally has the ahoge.
Infamously, the Osborn family of Spider-Man (seen above), who all have the same... "unique" hairstyle (stylized waves?). The one exception is Gabriel Stacey, the son of Norman Osborn and Gwen Stacey, and even in that case, it's likely because his father was originally intended to be Spider-Man himself.
Spider-Man has a mother-daughter example in Gabriel's sister Sarah; apparently black hairbands are genetic. Apart from the arguable quality of the story that introduced them, this may be part of the reason fans are hoping for a Retcon.
John Byrne at one point made it that the Sandman and Norman Osborn were distant cousins, solely because they had the same hairstyle.
Meet the Robinsons: The Robinsons all have exactly the same flick in their hair, even most of the women.
Harry Potter got his jet black messy hair from his father, James.
The Heap family in Septimus Heap all share straw-coloured curls. Likewise, the royal family all has long black hair.
Emperor Uriel Septim VII and his illegitimate son (or should we say... heir?) in The Elder Scrolls IV: Oblivion bear some facial resemblance, but have the exact same hairstyle despite having never met (there are only a limited number of hairstyles available to begin with, but it does help you get the feeling they're related). But it gets better in light of one popular fan theory: it's possibly a hint that the Prophet in Knights of the Nine is Tiber Septim, a.k.a. Talos himself.
Homestuck: the kids have very similar hairstyles to their guardians, and, of course, each other.
Gilgamesh Wulfenbach has the same unkempt frizz that his father Klaus has in Girl Genius.
In the American Dad! episode "The Kidney Stays In The Picture", it is revealed that Francine slept with another man right before her and Stan's wedding, meaning Hayley may not be his biological daughter. The one thing Haley and this man have in common? A bandana.