Ocarina of Time, Resident Evil 2, Final Fantasy VII, Final Fantasy Tactics, Banjo Kazooie, Majora's Mask, Paper Mario, Silent Hill, Dino Crisis, Crash, Rayman 2, Klonoa, Symphony of the Night, CTR, Diddy Kong Racing, etc.
...are still amazing games, even if you'd play them for the first time nowadays (which I did in several cases). In certain aspects they might even stomp many modern games. I can't respect any hobby gamer who rejects Generation 5 games or calls classics like that unplayable by default today. If you do, you're the equivalent of pseudo movie buffs who don't wanna watch black and white movies. Some games do in fact age badly, in particular anything going for realism like yearly sports titles. But a gem in many cases stays a gem, even with (not even always that) bad graphics. And tank controls can be learned within an hour, after that you're set forever. If something is truly unplayable nowadays, it was probably average to begin with. Maybe I wouldn't recommend any of the above to casuals or only half-interested gamers, but any hardcore gamer mustn't shy away from classics before the HD era, even if it's 3D, nor shit on entire generations because of biased reasons.