Gaming Soundtracks for Motivation or Relxation

It's probably more than a little weird that I like to listen to music from games.  Every time that someone walks into my classroom and I have gaming music on in the background, I know that they are confused.  Students tell me all the time that the music I play is "weird."  (Except the nerdy ones who recognize it)

Regardless of what other people think, there are some really great game soundtracks out there that are perfect for those times when you want to relax.  Part of the magic in listening to those soundtracks out of context is recalling all the fun you had while playing.

#1--The Elder Scrolls V:  Skyrim
Skyrim is one of those big, sprawling Bethesda games that always ends up making me feel ambivalent about the game itself.  Fortunately, the soundtrack offers some of the best music for roaming around and slaying dragons.  It's perfect for those times when you want to throw on some soothing background music while you're working.  If you're feeling the need for something a little more motivating you can skip to "Dragonborn" and relive the experience of shouting down a dragon.
Best tracks:
Motivation:  Dragonborn
Relaxation:  Kyne's Peace

#2--World of Warcraft
World of Warcraft has been around in some iteration since 2005.  Each new expansion has offered tons of new gameplay and a brand new soundtrack.  As someone who has spent many, many hours playing WoW, I have always enjoyed the music.  Each unique zone has it's own piece of music--whether it's the creepy, screechy sounds of the Undercity or the light, magical tones of Dalaran, the WoW soundtracks have always been the perfect punctuation to the sprawling, mythical world.
Best Tracks:
Motivation:  Arthas, My Son (from the Cinematic Intro)
Relaxation:  Song of Elune

#3--Deus Ex: Human Revolution
Deus Ex:  Human Revolution is another of those games that I can't say that I especially loved, but it does have a phenomenal soundtrack.  The OST manages to capture the feeling of living in the strange, futuristic world depicted in the game.  Unlike the other two soundtracks I mentioned, this one is much more electronic.
Best Tracks:
Motivation:  The Mole (I absolutely love this track)
Relaxation:  Home

#4--Transistor
Unlike the other OST's listed, Transistor features a mix of instrumental music from the game and vocal tracks.  Supergiant Games have made it a point to incorporate great music into their games and the vocal tracks are definitely the standouts.
Best Tracks:
Motivation:  Apex Beat
Relaxation:  Paper Boats