Games that could really do with a remaster
Daggerfall: Unplayable to all but the most dedicated with its antiquated controls and confusing interface
Xenogears: Shipped literally incomplete, never was completed, still regarded as one of the best games of all time regardless
Final Fantasy VII: Graphics quality doesn't do it justice, translation was a trainwreck and the story is near-impossible to follow
Final Fantasy VIII: Translation was a fender bender; definitely needs a retranslation that actually portrays Squall's character properly. Graphics hold up pretty well though.
Wild ARMS 2: Again, translation was a mess. Better than FFVII but Liz's speech is completely unintelligible and some of the story is hard to follow.
Pokemon gold/silver/crystal: Classics of the series, but many items didn't work properly and it could do with being put onto more modern systems
The Legend of Zelda: Translation made cryptic hints into unintelligible nonsense, and it would be an amazing game to see with a more vivid world than the NES could give it
Games that got a remaster, or one has been announced
Skyrim: Why? perfectly good quality on multiple relatively modern systems already at release.
Final Fantasy X/X-2: Again, the originals were pretty damn good and hold up just fine today
Final Fantasy VII (eventually): Hey, they got one right!
Dark Souls: Seems perfectly playable on the original. Why remake what's already fine?
Pokemon gold/silver/crystal: They got another one right! And they did a fantastic job of it too.
The Wind Waker: I don't see why this was remastered. The original is perfectly fine and the style makes HD-ness kind of redundant
Twilight Princess: Okay the amiibo is great and all but I don't think this one needed a remaster either.
Super Mario 64: Okay, I won't fault them for this one, they did a really good job remastering it and while I wouldn't say it really needed it it _is_ still a classic
Ocarina of Time and Majora's Mask: Same boat as SM64.
re: Games that got a remaster, or one has been announced
and this is what I see as a problem with the video game industry. At least with movies, you can copy your VHSs to DVDs pretty easily (if dubiously legally) so you don't need to keep old hardware around, and the quality of the graphics hasn't changed _that_ much, certainly not as much as it has with video games, so VHS quality is still perfectly acceptable today, even if higher quality would be preferred. But video games take a lot of human effort to bring up to the rapidly changing standards and that's a hard problem to solve.
the nintendo Virtual Console and Sony and Microsoft's versions thereof do a decent job of preserving classics, but they leave out a lot of lesser-known games (that really deserve to be known) and they're also all-digital, with no physical media for the games.