Needs more robots in here. Super Robot Wars has both excellent remixes of songs and awesome original ones.
Lion - Super Robot Wars Z2 Saisei-hen/Macross Frontier
Sorairo Days/Sky Blue Days - Super Robot Wars Z2 Hakai-hen/Tengen Toppa Gurren Lagann
Colors - Super Robot Wars Z2 Hakai-hen/Code Geass
Ignited - Super Robot Wars Z/Gundam SEED Destiny
Just Communication - Super Robot Wars Z2/Gundam Wing
Love is Far Away - Super Robot Wars Alpha 3/Dancouga
Edit: Nostalgia bonus go.
White Reflection - Super Robot Wars Alpha Gaiden/Gundam Wing
And if those don't count, did I mention they have a ton of amazing original songs made just for the games? Because they do.
Burning Red - Super Robot Wars MX
Wild Flight - Super Robot Wars Original Generations
Over the Time Flow - Super Robot Wars R/Super Robot Wars Original Generations
Another Time Diver - Super Robot Wars Alpha 3
Everywhere You Go - Super Robot Wars Alpha
Flapper Girl - Super Robot Wars Alpha Gaiden/Lord of Elemental
Neppu! Shippu! Cybuster - Super Robot Wars Alpha Gaiden/Lord of Elemental
Shinin' Heart - Super Robot Wars K
Other than GIANT ROBOTS FIGHTING OTHER GIANT ROBOTS, the instrumental remixes of existing songs and new songs they create really make the series enjoyable.