Anamanaguchi - As close to solid red as I have seen
"Searching for Atlantis" by Random - The rest of the album is good, but thats my favorite.
Virt - Choppastyle and Try are great ones
She - Got a lot of her music. "in time" and "touch and go" from coloris, and the single "traveling" are the best.
Rushjet1 - Space themed 8-bit, whats not to love?
"Du Finns" By Psilodump - Starts off slow, but gets better.
Mingebag Rave - From one of Lit Fuses movies. Weird, but a good ride.
"Haunted Candies" by Trash80 - Something else by the dude who did "Icarus"
Those are the best free rides I can think of at the moment. Feel free to share any you have.