One actress which I think is currently underrated is Sarah Hagan.
To date, she is best known for her recurring roles as Millie on
Freaks and Geeks and as Amanda the Potential on the seventh season of
Buffy The Vampire Slayer, as well as having a bit part in the movie Orange County.
I didn't really notice her on
F&G (even though I did watch that show), and I didn't really notice much at first during the original run of
Buffy Season Seven, but after reading a feature interview she did with
Buffy Magazine and checking her profile on IMDb, I decided to take a chance and watch reruns of the
Buffy episodes in which Amanda was featured, starting with "Potential" - and it was in that episode that I found Amanda (who was really adorable, quite funny and a little quirky) to be the only one that I liked out of all the Potentials introduced that season; it was also beginning with "Potential" that I started to like Sarah as well.
After
Buffy ended its run, Sarah did an episode of
Judging Amy, as well as some stage work and appearances at
Buffy conventions, before starting on her latest projects, an episode of the new medical series
Grey's Anatomy (playing a character called Devo) and the teen comedy/drama flick Odd Girl Out (where she will be reunited with
Buffy castmate Michelle Trachtenberg).
Although she has not had major roles in movies or played a regular role in a TV series yet, I think Sarah Hagan has it in her to become a success as an actress; she is young (just 20 y.o. right now), has developing talent, good comic timing, is adorable and has a certain cuteness to her. If she is successful and attracts more attention with her current acting projects, she could land more high-profile roles and become more well-known as an actress.