Pure Volume has been doing this for a few years now and it's still a popular site, though Facebook and Bandcamp have probably lessened the traffic some. All the green links below take you to the sampler page. Once there, just stroll through the playlist to find the tune you want. If it's a free download, just click where it says "free mp3".
2. Ribbons & Bows - ASTERIA
3. O Holy Night - HE IS WE
4. The Christmas Song - PLUG IN STEREO (ft. The Ready Set)
5. Mile High Christmas - BREATHE CAROLINA
6. Emmanuel - SLEEPERSTAR
7. Merry Christmas, Happy Holiday - ARTIST VS. POET
8. Carol Of The Bells - AUGUST BURNS RED
9. Let This Be A Merry Christmas - MY GENUINE FIND
10. Refuse To Break For Christmas Sake - BACK TO NORMAL
11. Christmas Time Again - AMELY
12. Yule Be Sorry - AARON GILLESPIE
13. O Holy Night - AS TALL AS LIONS
14. Maybe This Christmas - FOR ALL THOSE SLEEPING
15. Baby Please Come Home - ANBERLIN
16. @santa's playlist - LET'S GET IT
17. Carol Of The Bells - MAE
18. Christmas Brings Me Down - SPARKS THE RESCUE
19. It's Not Christmas Without You Here - WEATHERSTAR
20. Happy Holidays, You Bastard - ARTIST VS. POET
21. Epic Holiday - ANGELS AND AIRWAVES
22. Jesus Christ - BRAND NEW
23. Stocking Stuffer - OCEAN IS THEORY
24. Sleigh Bells & Reindeer - ACT AS IF
25. Santa Slays - FIGHT! FIGHT! FIGHT!
26. Christmas List - TRANSMIT NOW