A creepy cult classic that is often overlooked. It even had a special edition!
Game title: Castlevania
System: Nintendo 64
Developer: Konami CEK
Why it's so cool: I may be in the minority when I say this, but Castlevania for Nintendo 64 is a good game.
Sure the controls are a little clunky and the models are blocky with blurry texture maps, but the game is oozing with atmosphere and a compelling storyline that fits true to the series.
Castlevania 64, as it was unofficially known, featured two playable characters, Reinhardt and Carrie, on their own personal quests to hunt down and destroy Count Dracula. They each met various supporting characters in their own stories that unfolded as the levels progressed.

While a 3D game, the style was somewhat linear and more akin to the classic 2D games in the series, with increasingly challenging levels to traverse and boss fights to signify the end of a stage. The 2D control feel carried over to 3D quite well, players would use their trusty whip or demon-seeking energy blasts to fend off various monstrosities, and each of the classic sub-weapons could also be collected and used. Combat had a helpful targeting system much like the one in Ocarina of Time, though unfortunately the platforming sections suffered from some heavy jumping mechanics and random character rotation, making them tricky to navigate. Thankfully, it was nothing that couldn't be overcome with practice and skill, and thorough players could find and manage rare items for emergency health restorations and puzzle-related spell cards to change the time of day, among other things. This was also one of the first games in the series to feature vampires besides the Count himself as semi-regular enemies, and a new status ailment called Vamp was added to the series. When a player was bitten by a vampire, he'd be infected and if it wasn't tended to quickly, the player would turn into a demon and get Game Over.
The game was considerably difficult (almost even comparable to the original NES Castlevania games at times!) and had several endings to discover for each character depending on the time taken and various decisions made throughout the course of the game. There was even an optional boss that would only appear if you made too many transactions with a demon selling items to adventurers in each level.

Worth Mentioning: Just under a full year after the release of this game came a pseudo-sequel special edition called Castlevania: Legacy of Darkness. This game centered around a new playable character named Cornell, a young werewolf on a quest to save his human sister from Dracula's castle. Besides the new ability to go wolf-mode on enemies for a limited time, the game featured new levels and some remixes of the original version's levels. There was also a fourth playable character who had a mini-quest to search the levels for some missing children kidnapped from a nearby village, and once both Cornell and Henry's stories had been completed, Reinhardt and Carrie's quests became unlocked to play.
If either version of the game was to be considered for Virtual Console, this would be the better choice, but there is just enough difference in the existing levels and content for collectors such as myself to want both games to appear on Wii!

So why isn't it out yet? Despite being unfairly blasted by some critics (who, in my personal opinion, couldn't be bothered learning the controls and therefore sucked at the game), CV64 received fairly good reviews. I think the main problem here is a hardware issue. Most of Konami's games on the Nintendo 64 required the Controller Pak in order to save the game, something that hasn't been emulated on Virtual Console. This is the same reason why ghost data could not be saved in the VC version of Mario Kart 64. There are ways around this, of course. It shouldn't be too difficult to modify the game to look for save data in the stored Wii memory file rather than the controller. After all, Pokémon Snap's Virtual Console ROM was retooled to be able to send photos to the Wii message board.