For some of my friends:
"Battle 2" from Final Fantasy III
"Kraid's Lair" from Metroid
"Edgar and Sabin's Theme" from Final Fantasy VI (this one suffered during the compression, so 'll have to tweak it some more)
For my dad:
"Derezzed" from Tron: Legacy (which actually came out amazingly well)
(Can't find a video for it, all of them are of a longer, 4 minute version. Wonder why that version wasn't on the OST my dad bought OR on the R3C0NF1GUR3D disk.)
I also wanted to make one of these the ringtone of my friend who introduced me to Friendship is Magic, but I forgot he didn't have a cellphone, so now they're just kinda sitting around on my phone:
"Pinkie's Singing Telgram (8-bit)" by RainbowCrash88 (original by Daniel Ingram)(this one also suffered a bit, need to fix the dips and peaks in the sound)
"Call Upon the Seaponies (EuroSHOOBEDOO Mix)" By Odyssey, aka Eurobeat Brony, aka T.Stebbins (original by heck-if-I-know-because-I-did-not-do-the-research)(this one really took a beating from the compression. Not as horrendous as it could be, but the sound is very tinny and garbled. Simple and/or 8-bit music seems to work best.)