For the last six seasons, Glee has brought joy, tears, laughs and frustration (basically the whole spectrum of human emotion) to our lives. But after the characters, the most important thing Glee gave us is the music.

We already rounded up the Fox series' 10 best-selling downloads, and now we're taking a look at the 10 best-selling downloads per character from the Glee cast. All of this data comes from Nielsen Music and is current for the sales period ending March 15, 2015.

To be clear, we're not including group numbers (a song where three or more take lead vocal) and we're only counting each character once. So while Gwyneth Paltrow's Holly would have made the list twice (with "Forget You" and "Landslide"), we've only included her best-selling digital song.

'Glee' Graduates at the Head of the Class on the Billboard Hot 100

Check 'em out in the graphic above. Sadly, not every major Glee character made the top 10. Artie (Kevin McHale) just missed it with his best-seller "Billionaire," as did Will Schuster's (Matthew Morrison) version of "Over the Rainbow" and Jesse St. James' (Jonathan Groff) "Rolling in the Deep" cover.

While it might surprise some, the best-selling "solo" spotlight from a Glee character doesn't even come from a series regular. Paltrow, playing substitute teacher Holly, earns the top slot on this list with her clean cover of CeeLo Green's "Forget You."

After the No. 1 spot comes a series regular -- but not a student from McKinley High. Darren Criss' lead vocal on Katy Perry's "Teenage Dream," backed by the Dalton Academy Warblers, became one of its most insanely popular downloads -- it's been purchased 652,000 times.

Next up is Rachel and Kurt, whose dueling solo spots on the Wicked classic "Defying Gravity" also passed the half-million mark in downloads. Speaking of Wicked-ly talented, Idina Menzel's Glee character, Shelby, is up next. Her duet with her estranged daughter Rachel on Lady Gaga's "Poker Face" moved 410,000 downloads.

A third song prominently featuring Rachel is included on this list: the West Side Story/TLC mashup "I Feel Pretty/Unpretty" is at No. 6 because it boasts the best-selling solo spotlight from Quinn (Dianna Agron).

As for the late Cory Monteith, Finn's biggest solo seller is his version of "Jessie's Girl," which Finn sang to/about Rachel. In the episode, Rick Springfield's "Jessie" doubled as Jesse St. James, who Rachel was romantically involved with at the time.

Santana's (Naya Rivera) stunning solo turn on "Valerie" -- a song originally from the Zutons that Glee presented in the style of the Mark Ronson/Amy Winehouse cover -- moved 272,000 downloads. That's followed closely by Puck's "personal tribute to Jewish musical icon" Neil Diamond with the immortal "Sweet Caroline."

'Glee' Casts 10 Best-Selling Downloads

Mercedes (Amber Riley) and Tina (Jenna Ushkowitz) found their biggest spotlight song when they shared lead on Florence + the Machine's "Dog Days Are Over." And another track featuring Quinn, "Lucky," wraps the list. We've included it because it's the best-selling download from Sam (Chord Overstreet).

It's worth pointing out that much like Glee's best-rated episodes, these massive-selling songs come from Glee's first two years: Six of these songs are from season 2, and four from season 1.

As for our favorite songs from Glee, check out the Must-Hear Music podcast's special Glee episode below, where we chat about our favorite songs from the series.