I have a few tracks that I hum from the N64 'vanias.
First off, let's start with the obvious ones:
-The Art Tower (probably the best version of "Sinking Old Sanctuary" yet)
-Third Struggle: Dance of Illusions (I like the chorus used in this one)
-Sign of Blood Pulse + Opposing Bloodlines (the entire intro including the violin - first part is also used in Circle of the Moon)
-Second Struggle: Dancing in Phantasmic Hell (DraculaX Boss Battle)
And now for the not-so obvious ones:
-Toothed Wheel (The Clock Tower)
-The Castle Center (or "The Wolf Revealed" in LoD, though there are variations to it, like in the staff roll, or in the tower of Ruins)
-Rose (when you first meet Rose, which is a nice tune)
DRACULA APOCALYPSE -ORIGINAL GAME SOUNDTRACK- 09 Rose-Lamented Rose (Rosa's suicide attempt)
-The Demon Salesman (a short tune for Renon's conversation and other conversations with 'odd' characters, though has an intro and reprise towards the end of the game)
-Fourth Struggle: Concert of Another Dimension (Final Dracula and Behemos battle)
-Malus (his tune is cool but odd)
-Schneider's Good Ending
DRACULA APOCALYPSE -ORIGINAL GAME SOUNDTRACK- 35 Schneider's Good Ending-Carrie's Good Ending (similar but different than Schneider's)
DRACULA APOCALYPSE -ORIGINAL GAME SOUNDTRACK- 33 Carrie's Good Ending-Annex: Silent Madness (the Villa) **Lightning Strikes**
-Invisible Sorrow (Underground Tunnel)
-Tower of Sorcery
-Tower of Duels
-Underground Waterway (sounds like a mix of "Chaconne C. Moll and the James Bond theme xD)
-Tower of Science
-Shudder (used also in CotM against the Cerberus hound, short tune)
-First Struggle: Boss Battle
-Watchtower (The Castle Wall)
And for Legacy Only:
-The Legacy (version of Bloody Tears)
Castlevania Legacy of Darkness - 008 - The Legacy-The Outer Wall (has a little Vampire Killer in there in terms of chords)
-Escape the Maze Garden:
Castlevania Legacy of Darkness - 004 - Maze GardenWhile a lot of the tracks are indeed pretty ambient in comparison to other games, there are many that carry a lot of power and emotion to them.