Rumour Has It/Someone Like You
The episode "Mash Off" gave us some of the show's most iconic performances, including this one, which comes right at the heels of Santana being publicly outed as a lesbian. You can feel her anger in this performance, and it's an all-time fave.
Valerie
Rivera sang this uptempo version of "Valerie" twice—once in season two, as part of an elaborate performance with the rest of the glee club, and once in season five, all by herself. Both are incredible, but the season five performance really shows off just how effortless a performance like this appeared to be for her.
Smooth Criminal
There are almost no words to describe Santana's vocals in this face off against the future Flash (Grant Gustin). Just incredible.
Mine
One of Taylor Swift's best songs plus the fact that Santana was about to break up with Brittany (due to distance) make for one hell of an emotional performance.
Don't Rain on My Parade
Rachel Berry (Lea Michele) thought "Don't Rain on My Parade" was her domain and certainly wasn't expecting Santana to audition for Funny Girl, and you can see the surprise on her face as Santana recreates Rachel's iconic season one performance...and blows it out of the water.
Songbird
Beyond being one of Naya Rivera's best performances, this might be one of the best performances from the whole show. Santana sang this to Brittany (Heather Morris) as they were still figuring out their feelings for each other, in an episode that served as a tribute to Fleetwood Mac's album Rumours.
Cold-Hearted
Things got a bit sexier later in the series as everyone grew up and moved to New York, and Santana (and Rivera) proved she could really do it all with this Paula Abdul number, complete with a truly impressive dance routine.
River Deep, Mountain High
Naya Rivera and Amber Riley went together like peanut butter and jelly, their voices complimented each other and this performance, in character as Santana and Mercedes in an effort to win free dinner, was a show stopper.
Back to Black
It felt like Naya Rivera never met an Amy Winehouse song she couldn't conquer, despite the fact that Jesse St. James (Johnathan Groff) felt this performance lacked "emotional depth." He was wrong.
Landslide
Holly (Gwyneth Paltrow) had the lead vocals here, but you barely notice because all you're focusing on is Santana's face as she and Brittany provide the harmonies. Santana picked the song to show Brittany how she felt about her, which you can see from her expression throughout the whole performance.
If I Die Young
This one's always hard to watch, but worth it. After the death of Cory Monteith and his character, Finn Hudson, Santana performed The Band Perry's "If I Die Young" in front of the rest of the glee club, breaking down into screaming sobs in the middle of it. A showcase of both Rivera's singing and her acting skills.