So there is plenty of music that I feel is overlooked mostly because the game did poorly. Here are some examples

Mario and Sonic at the Sochi Winter Olympics 

Mushroom Bridge

Buoy Base Galaxy

Bowser's Galaxy Generator

Super Mario Land medley

Anarchy Reigns

Days of Old

Here We Go

My Town, My City

Etrian Odyssey Untold - The battlefield that Never Sleeps

Etrian Odyssey 4- Battlefield- Storm

Most of the Dynasty Warriors games and their various spin offs have incredible soundtracks, but none more so than the Fist of the North Star games. MASA and Yamada outdid themselves in capturing the feel of the manga/anime. If these songs don't make you cry MANLY TEARS, then you are already dead inside.

Main Theme

Accepted Fate

Seven Scars

To Each Road

Without Warrant

And, of course, a killer arrangement of Ai wo Torimodose

Skies of Arcadia - Legendary Sinking Continent 

PL & The Curious Village - Layton's Theme

Katamari Damay - Que Sera Sera

To The Moon - Main Theme

I know a lot of people do appreciate the music in Link to the Past, but I feel like it's too often overshadowed by Ocarina of Time. OoT gets the gold for sheer number of memorable themes, but I feel like LttP had some of the most awesomely composed music, which sounded so great with that chip. The Dark World theme in particular is a classic, and the Forest theme is my favorite Zelda song of all time.

Nier... the game no one played...Every song...

I really liked the soundtracks for Dune 2000 and Emperor: Battle for Dune...

The ost of Nier is one of the best i've ever heard in videogames and quite unique.

http://youtu.be/XgMRNiEPPYg

http://youtu.be/u5xZbJDZZo4

The Last Blade games:

https://www.youtube.com/watch?v=LwWaZ4jybN8&list=PLyySTEbJ4PhfKuuZo0T5KuPnOZAqepWSp&index=3

https://www.youtube.com/watch?v=yM8yLssxmOU&list=PLyySTEbJ4Phe8C5R6oXAJhbiScH86f8DJ