You can officially play the original Doom on almost every post-1993 console, and thanks to intrepid hackers around the world you can unofficially play it on practically anything with a processor.
But that's not the case for 1997's Doom 64, which has only ever been officially available on the Nintendo 64. The game is finally getting a re-release on the Switch later this year, and while the brand-new Doom Eternal may be more enticing, you shouldn't skip over Doom 64 under the assumption that it's just "more Doom."
Doom 64 is often lumped in with the Doom ports for the SNES, Jaguar, and PlayStation in spite of the fact that it's an entirely new game. It was developed by Midway, not id Software, and is closer in spirit to a true sequel than a console afterthought or spin-off title. The game is set after Doom 2, though the franchise's scant storytelling by '97 means a wealth of Doom lore isn't a prerequisite for playing. The engine was heavily modified to take advantage of the N64's graphics hardware, and unlike the console release of the original Doom, all of Doom 64's levels are exclusive to the game and were never officially ported to another Doom release since.
The modified Doom 64 engine actually beat John Carmack's Quake 2 engine to having colored lighting as a key feature, and it was employed to great effect throughout the game's levels. On the whole, Doom 64 is a dark game and its levels, ranging from science facilities lit in sickly green to temples bathed in the blood-red light of hell, come across as far creepier than those of Doom or Doom 2.
Unfortunately, the dim lighting means that a lot of footage of Doom 64 is difficult to make out, such as this 2013 Summer Games Done Quick speedrun that's both a good and bad example. The game looks considerably brighter in the announcement trailer for the Switch port, so hopefully that's something players will have the ability to tweak to their liking.
Doom 64 also abandons the original sprite and texture sets of Doom and Doom 2 for new unique art and trades those games' MIDI metal songs for an eerie ambient soundtrack by composer Aubrey Hodges. In every respect, Doom 64 was the furthest an official entry in the series strayed from the comparatively upbeat and over-the-top demon slaying of the 1993 original until Doom 3.
Whether attracted by the game's particular atmosphere or just hoping to play all Doom has to offer on one platform, a number of unofficial fan efforts to port Doom 64 to PC have been undertaken over the years. Even if the port only comes to the Switch, it's possible that Bethesda may take legal steps to pull these PC versions offline—but the fact that we're talking about a real Doom 64 port in 2019 at all is vindication for everyone who has championed and supported the game over the last 22 years.
For now, it looks like the Switch will be the only system where you can officially play Doom, Doom 2, Doom 64, Doom 3, the 2016 Doom, and Doom Eternal all in one place. Doom 64 and Doom Eternal will both be released on November 22, 2019.