Heroes of Might and Magic 4's water theme [http://www.youtube.com/watch?v=o7VRWpr1UHw]. I yet have to meet someone who doesn't love that one. All HOMAM music is wicked sick, but the soundtrack to game number four truly has something special.
Also, there's this [http://www.youtube.com/watch?v=bAKJ4XKSKFw], with the part everyone (who'se played SC) knows starting at 3:54 (or 4:30 if you want to skip the 'intro').
Last but not least, Warcraft 2, 3 and WoW all have some memorable songs for me. This one [http://www.youtube.com/watch?v=K82bvaAMemA] is just effing nostalgic and while less impressive, the music from the main menu [http://www.youtube.com/watch?v=BZAXwQ_Kyco] has also left a mark on me. Moving on to Warcraft 3, songs like Human theme [http://www.youtube.com/watch?v=OXajx7l4VxE] are a completely different style but still manage to really grab me, even if it's in a completely different way. Doomhammer's Legacy [http://www.youtube.com/watch?v=PomX6iTT39I] reminds me of the first time I did the Orc campaign (of which the first few levels are about 'stranding' on a completely new land and exploring it) which is, again in a different way, very nostalgic. Then, moving onto WoW, the theme song, Legends of Azeroth [http://www.youtube.com/watch?v=tqsazZUbt9s], is another one that I will never forget. And if you've skipped over all songs in my post so far, I just dare you to listen to The Shaping of the World [http://www.youtube.com/watch?v=NhrxGCMzRL0] and *not* find it epic. And this is the point where I have to stop myself from posting the other 28 songs on the OST album because literally every single one of them gives me shivers. Instead, I'll just stick to The Sin'dorei [http://www.youtube.com/watch?v=wCe4uisTtbo] from the game's first expansion, a song which explains the entire Blood Elf race in its three main emotions - beauty, melancholy and wickedness.
Anyway, thanks for the post OP - you've given me another opportunity to re-examine part of my roots and the reason why I love these franchises so much. I'll leave the thread with saying that if a game developer allows players to play eight races and gives them such a strong background and culture that people really feel they 'belong' to any one of them, how can you not respect him?