* NES
* SNES
* N64
* Sega Genesis
I guess you could argue that Gamecube isn't represented yet, but that's the only major out of date system that isn't included (Understanding that almost any game playable on the WiiU is also on the Switch).
I'd say it takes a very narrow view of what's "worth playing" to say that.
To me, the Switch Online emulation services are defined by what they're missing.
Nintendo IPs: Donkey Kong 64. Diddy Kong Racing. Kirby 64 (Crystal Shards). Any of the Pokemons. Any of the Bombermans. Excitebike 64.
Non-Nintendo IPs: GoldenEye. Any of the Tony Hawk Pro Skaters[1]. Either Duke Nukem. Doom 64[2]. The second Banjo-Kazooie. Wave Race. Earthworm Jim.
[1]: Pro Skater 1 & 2 have been released for the Switch separately from NSO; $40 for both of them as a bundle. 3 has not been released for the Switch.
[2]: Doom 64 has been released for the Switch separately from NSO; for $5.
Likewise, I assume the Doom 64 release is a source-port, not emulated.
Super Mario RPG isn’t.
Chrono Cross, Final Fantasy 6, Mega Man X, TMNT. I’d even pay a couple bucks to waste an hour playing Bart’s Nightmare again.
Pokémon is a nonentity.
It’d be a hell of a nostalgia trip to play Rampage, IronSword, Monster Party, Linus Spacehead, Treasure Island Dizzy, Super Robinhood, or Boomerang Kid.
It does have Radical Dreamers though.
The N64 library is quite small, and only has a handful of games. I mean, the ideal N64 library is also quite small: only 306 North American or PAL (~English language) games were ever released. But 306 seems so eminently achievable that it makes the small selection of games on the service that much more dramatic.