PeriperiSauce Brown aka. "Peri" (played by Nicola Bryant) was the rather pleasant-to-look-at companion of the Fifth and Sixth Doctor's.
Peri first appears in 1984's Planet of Fire and dies in 1986's Mindwarp. SPOILERS.
She also appears at the end of The Ultimate Foe thanks to JNT and some stock footage.
Peri brought two good things to her role as the companion in the 80s, neither of which were her “American” accent nor her whiny personality.
She later married Brian Blessed - well either that or died, depending on which The Trial of a Pie Lord ending you consider to be more canon.
After regenerating the Sixth Doctor warmly greeted Peri by strangling her. If you listened to her talk long enough, you'd probably wish to do the same. See The Twin Dilemma for more details.
Listen to Peri and the Piscon Paradox pleb, because she makes a good go of things over on the audios. Also true of the Sixth Doctor. According to some guy.
[edit; I can confirm. It has Peri mockingly imitating the Fifth Doctor and it has based Colin Baker getting irritated by him. Lulz were had. Also feelz.]
Only downside is the medium doesn't allow you to see her tatas, ergo making the claim that she's better in the audios moot.
Peri's era frequently suffered from shitty writing but she was always delicious to look at (and hey at least she got to be in Androzani). Also Nicola Bryant is based (and still smoking hot.)