Here's some of the tracks in my playlist currently: (EDIT - Added comments)
Toshikazu Tanaka - [Metal Slug 5 OST] - Windy DayMetal Slug has some of the greatest game music around, especially 4, 5, and 3D. Check them out!
Magical Trick Society - [CADENZA] - Pursuit ~ CorneredThe greatest remix of the greatest Phoenix Wright track. OBJECTION!
Frontier Aja - [Legend of the Scarlet Devil Castle: Scarlet Symphony OST] - Chains on my Right Hand, Madness in my Left Hand [Vs Flandre]Not a fan of the freeform style in the first minute, but at 1:10, this turns into pure gold.
cobu - [Gensou Shoujo Taisen Scarlet OST] - In Still Time ~ Blue Sea of 53 MinutesReally nice combination of instruments and tune make this a great track.
Dark PHOENiX - [Arrow Rain] - Plain AsiaCrazy awesome piano stuff here. I really love the tune, too.
Falcom Sound Team jdk - [Ys Seven OST] - Innocent Primeval BreakerThere's also really good stuff in some of the Ys soundtracks, but this is my favourite.
Level 99, Moonlapse, OA - [OCRemix] - Ecco: The Tides of Time - Waves of StoneFantastic overall feel to this one.
Manabu Namiki - [Trauma Center: Under The Knife 2 OST] - Encroaching ShadowsBy the same guy who did the Metal Slug 6 soundtrack, this is a surprisingly catchy tune.
Yukihiro Jindo - [Ys: The Oath in Felghana OST] - Valestein CastleAwesome theme tune with some rockin' electric guitar.
Toshikazu Tanaka - [Metal Slug 3D OST] - Coal Mine MarkSee comments on Tanaka's work above, another fantastic entry in the Metal Slug series (the music, mind you - not the game, which was shit).
TAM & Keigo Kanzaki - [Touhou Violin Rock] - Walking the Streets of a Former HellI love the violin, this track combines excellent violin work with an excellent tune.
Gaijin Games - [Bit.Trip Runner OST] - Blackout City (feat. Anamanaguchi)Finish up the list with a good old modern chiptune. The last half of this one is especially good.